chapter 2 exercise
大学英语学术写作参考答案人大版
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Exercise 1 chapter1-chapter3
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数据库系统基础教程(第二版)课后习题答案2
Database Systems: The Complete BookSolutions for Chapter 2Solutions for Section 2.1Exercise 2.1.1The E/R Diagram.Exercise 2.1.8(a)The E/R DiagramKobvxybzSolutions for Section 2.2Exercise 2.2.1The Addresses entity set is nothing but a single address, so we would prefer to make address an attribute of Customers. Were the bank to record several addresses for a customer, then it might make sense to have an Addresses entity set and make Lives-at a many-many relationship.The Acct-Sets entity set is useless. Each customer has a unique account set containing his or her accounts. However, relating customers directly to their accounts in a many-many relationship conveys the same information and eliminates the account-set concept altogether.Solutions for Section 2.3Exercise 2.3.1(a)Keys ssNo and number are appropriate for Customers and Accounts, respectively. Also, we think it does not make sense for an account to be related to zero customers, so we should round the edge connecting Owns to Customers. It does not seem inappropriate to have a customer with 0 accounts;they might be a borrower, for example, so we put no constraint on the connection from Owns to Accounts. Here is the The E/R Diagram，showing underlined keys andthe numerocity constraint.Exercise 2.3.2(b)If R is many-one from E1 to E2, then two tuples (e1,e2) and (f1,f2) of the relationship set for R must be the same if they agree on the key attributes for E1. To see why, surely e1 and f1 are the same. Because R is many-one from E1 to E2, e2 and f2 must also be the same. Thus, the pairs are the same.Solutions for Section 2.4Exercise 2.4.1Here is the The E/R Diagram.We have omitted attributes other than our choice for the key attributes of Students and Courses. Also omitted are names for the relationships. Attribute grade is not part of the key for Enrollments. The key for Enrollements is studID from Students and dept and number from Courses.Exercise 2.4.4bHere is the The E/R Diagram Again, we have omitted relationship names and attributes other than our choice for the key attributes. The key for Leagues is its own name; this entity set is not weak. The key for Teams is its own name plus the name of the league of which the team is a part, e.g., (Rangers, MLB) or (Rangers, NHL). The key for Players consists of the player's number and the key for the team on which he or she plays. Since the latter key is itself a pair consisting of team and league names, the key for players is the triple (number, teamName, leagueName). e.g., JeffGarcia is (5, 49ers, NFL).Database Systems: The Complete BookSolutions for Chapter 3Solutions for Section 3.1Exercise 3.1.2(a)We can order the three tuples in any of 3! = 6 ways. Also, the columns can be ordered in any of 3! = 6 ways. Thus, the number of presentations is 6*6 = 36.Solutions for Section 3.2Exercise 3.2.1Customers(ssNo, name, address, phone)Flights(number, day, aircraft)Bookings(ssNo, number, day, row, seat)Being a weak entity set, Bookings' relation has the keys for Customers and Flights and Bookings' own attributes.Notice that the relations obtained from the toCust and toFlt relationships are unnecessary. They are:toCust(ssNo, ssNo1, number, day)toFlt(ssNo, number, day, number1, day1)That is, for toCust, the key of Customers is paired with the key for Bookings. Since both include ssNo, this attribute is repeated with two different names, ssNo and ssNo1. A similar situation exists for toFlt.Exercise 3.2.3Ships(name, yearLaunched)SisterOf(name, sisterName)Solutions for Section 3.3Exercise 3.3.1Since Courses is weak, its key is number and the name of its department. We do not have arelation for GivenBy. In part (a), there is a relation for Courses and a relation for LabCourses that has only the key and the computer-allocation attribute. It looks like:Depts(name, chair)Courses(number, deptName, room)LabCourses(number, deptName, allocation)For part (b), LabCourses gets all the attributes of Courses, as:Depts(name, chair)Courses(number, deptName, room)LabCourses(number, deptName, room, allocation)And for (c), Courses and LabCourses are combined, as:Depts(name, chair)Courses(number, deptName, room, allocation)Exercise 3.3.4(a)There is one relation for each entity set, so the number of relations is e. The relation for the root entity set has a attributes, while the other relations, which must include the key attributes, have a+k attributes.Solutions for Section 3.4Exercise 3.4.2Surely ID is a key by itself. However, we think that the attributes x, y, and z together form another key. The reason is that at no time can two molecules occupy the same point.Exercise 3.4.4The key attributes are indicated by capitalization in the schema below:Customers(SSNO, name, address, phone)Flights(NUMBER, DAY, aircraft)Bookings(SSNO, NUMBER, DAY, row, seat)Exercise 3.4.6(a)The superkeys are any subset that contains A1. Thus, there are 2^{n-1} such subsets, since each of the n-1 attributes A2 through An may independently be chosen in or out.Solutions for Section 3.5Exercise 3.5.1(a)We could try inference rules to deduce new dependencies until we are satisfied we have them all.A more systematic way is to consider the closures of all 15 nonempty sets of attributes.For the single attributes we have A+ = A, B+ = B, C+ = ACD, and D+ = AD. Thus, the only new dependency we get with a single attribute on the left is C->A.Now consider pairs of attributes:AB+ = ABCD, so we get new dependency AB->D. AC+ = ACD, and AC->D is nontrivial. AD+ = AD, so nothing new. BC+ = ABCD, so we get BC->A, and BC->D. BD+ = ABCD, giving usBD->A and BD->C. CD+ = ACD, giving CD->A.For the triples of attributes, ACD+ = ACD, but the closures of the other sets are each ABCD. Thus, we get new dependencies ABC->D, ABD->C, and BCD->A.Since ABCD+ = ABCD, we get no new dependencies.The collection of 11 new dependencies mentioned above is: C->A, AB->D, AC->D, BC->A, BC->D, BD->A, BD->C, CD->A, ABC->D, ABD->C, and BCD->A.Exercise 3.5.1(b)From the analysis of closures above, we find that AB, BC, and BD are keys. All other sets either do not have ABCD as the closure or contain one of these three sets.Exercise 3.5.1(c)The superkeys are all those that contain one of those three keys. That is, a superkey that is not a key must contain B and more than one of A, C, and D. Thus, the (proper) superkeys are ABC, ABD, BCD, and ABCD.Exercise 3.5.3(a)We must compute the closure of A1A2...AnC. Since A1A2...An->B is a dependency, surely B is in this set, proving A1A2...AnC->B.Exercise 3.5.4(a)Consider the relationThis relation satisfies A->B but does not satisfy B->A.Exercise 3.5.8(a)If all sets of attributes are closed, then there cannot be any nontrivial functional dependenc ies. For suppose A1A2...An->B is a nontrivial dependency. Then A1A2...An+ contains B and thus A1A2...An is not closed.Exercise 3.5.10(a)We need to compute the closures of all subsets of {ABC}, although there is no need to think about the empty set or the set of all three attributes. Here are the calculations for the remaining six sets: A+ = AB+ = BC+ = ACEAB+ = ABCDEAC+ = ACEBC+ = ABCDEWe ignore D and E, so a basis for the resulting functional dependencies for ABC are: C->A and AB->C. Note that BC->A is true, but follows logically from C->A, and therefore may be omitted from our list.Solutions for Section 3.6Exercise 3.6.1(a)In the solution to Exercise 3.5.1 we found that there are 14 nontrivial dependencies, including the three given ones and 11 derived dependencies. These are: C->A, C->D, D->A, AB->D, AB-> C, AC->D, BC->A, BC->D, BD->A, BD->C, CD->A, ABC->D, ABD->C, and BCD->A.We also learned that the three keys were AB, BC, and BD. Thus, any dependency above that does not have one of these pairs on the left is a BCNF violation. These are: C->A, C->D, D->A, AC->D, and CD->A.One choice is to decompose using C->D. That gives us ABC and CD as decomposed relations. CD is surely in BCNF, since any two-attribute relation is. ABC is not in BCNF, since AB and BC are its only keys, but C->A is a dependency that holds in ABCD and therefore holds in ABC. We must further decompose ABC into AC and BC. Thus, the three relations of the decomposition are AC, BC, and CD.Since all attributes are in at least one key of ABCD, that relation is already in 3NF, and no decomposition is necessary.Exercise 3.6.1(b)(Revised 1/19/02) The only key is AB. Thus, B->C and B->D are both BCNF violations. The derived FD's BD->C and BC->D are also BCNF violations. However, any other nontrivial, derived FD will have A and B on the left, and therefore will contain a key.One possible BCNF decomposition is AB and BCD. It is obtained starting with any of the four violations mentioned above. AB is the only key for AB, and B is the only key for BCD.Since there is only one key for ABCD, the 3NF violations are the same, and so is the decomposition.Solutions for Section 3.7Exercise 3.7.1Since A->->B, and all the tuples have the same value for attribute A, we can pair the B-value from any tuple with the value of the remaining attribute C from any other tuple. Thus, we know that R must have at least the nine tuples of the form (a,b,c), where b is any of b1, b2, or b3, and c is any of c1, c2, or c3. That is, we can derive, using the definition of a multivalued dependency, that each of the tuples (a,b1,c2), (a,b1,c3), (a,b2,c1), (a,b2,c3), (a,b3,c1), and (a,b3,c2) are also in R.Exercise 3.7.2(a)First, people have unique Social Security numbers and unique birthdates. Thus, we expect the functional dependencies ssNo->name and ssNo->birthdate hold. The same applies to children, so we expect childSSNo->childname and childSSNo->childBirthdate. Finally, an automobile has a unique brand, so we expect autoSerialNo->autoMake.There are two multivalued dependencies that do not follow from these functional dependencies. First, the information about one child of a person is independent of other information about that person. That is, if a person with social security number s has a tuple with cn,cs,cb, then if there isany other tuple t for the same person, there will also be another tuple that agrees with t except that it has cn,cs,cb in its components for the child name, Social Security number, and birthdate. That is the multivalued dependencyssNo->->childSSNo childName childBirthdateSimilarly, an automobile serial number and make are independent of any of the other attributes, so we expect the multivalued dependencyssNo->->autoSerialNo autoMakeThe dependencies are summarized below:ssNo -> name birthdatechildSSNo -> childName childBirthdateautoSerialNo -> autoMakessNo ->-> childSSNo childName childBirthdatessNo ->-> autoSerialNo autoMakeExercise 3.7.2(b)We suggest the relation schemas{ssNo, name, birthdate}{ssNo, childSSNo}{childSSNo, childName childBirthdate}{ssNo, autoSerialNo}{autoSerialNo, autoMake}An initial decomposition based on the two multivalued dependencies would give us {ssNo, name, birthDate}{ssNo, childSSNo, childName, childBirthdate}{ssNo, autoSerialNo, autoMake}Functional dependencies force us to decompose the second and third of these.Exercise 3.7.3(a)Since there are no functional dependencies, the only key is all four attributes, ABCD. Thus, each of the nontrvial multivalued dependencies A->->B and A->->C violate 4NF. We must separate out the attributes of these dependencies, first decomposing into AB and ACD, and then decomposing the latter into AC and AD because A->->C is still a 4NF violation for ACD. The final set of relations are AB, AC, and AD.Exercise 3.7.7(a)Let W be the set of attributes not in X, Y, or Z. Consider two tuples xyzw and xy'z'w' in the relation R in question. Because X ->-> Y, we can swap the y's, so xy'zw and xyz'w' are in R. Because X ->-> Z, we can take the pair of tuples xyzw and xyz'w' and swap Z's to get xyz'w and xyzw'. Similarly, we can take the pair xy'z'w' and xy'zw and swap Z's to get xy'zw' and xy'z'w.In conclusion, we started with tuples xyzw and xy'z'w' and showed that xyzw' and xy'z'w must also be in the relation. That is exactly the statement of the MVD X ->-> Y-union-Z. Note that the above statements all make sense even if there are attributes in common among X, Y, and Z.Exercise 3.7.8(a)Consider a relation R with schema ABCD and the instance with four tuples abcd, abcd', ab'c'd, and ab'c'd'. This instance satisfies the MVD A->-> BC. However, it does not satisfy A->-> B. For example, if it did satisfy A->-> B, then because the instance contains the tuples abcd and ab'c'd, we would expect it to contain abc'd and ab'cd, neither of which is in the instance.Database Systems: The Complete BookSolutions for Chapter 4Solutions for Section 4.2Exercise 4.2.1class Customer {attribute string name;attribute string addr;attribute string phone;attribute integer ssNo;relationship Set<Account> ownsAcctsinverse Account::ownedBy;}class Account {attribute integer number;attribute string type;attribute real balance;relationship Set<Customer> ownedByinverse Customer::ownsAccts}Exercise 4.2.4class Person {attribute string name;relationship Person motherOfinverse Person::childrenOfFemalerelationship Person fatherOfinverse Person::childrenOfMalerelationship Set<Person> childreninverse Person::parentsOfrelationship Set<Person> childrenOfFemaleinverse Person::motherOfrelationship Set<Person> childrenOfMaleinverse Person::fatherOfrelationship Set<Person> parentsOfinverse Person::children}Notice that there are six different relationships here. For example, the inverse of the relationship that connects a person to their (unique) mother is a relationship that connects a mother (i.e., a female person) to the set of her children. That relationship, which we call childrenOfFemale, is different from the children relationship, which connects anyone -- male or female -- to their children.Exercise 4.2.7A relationship R is its own inverse if and only if for every pair (a,b) in R, the pair (b,a) is also in R. In the terminology of set theory, the relation R is ``symmetric.''Solutions for Section 4.3Exercise 4.3.1We think that Social Security number should me the key for Customer, and account number should be the key for Account. Here is the ODL solution with key and extent declarations.class Customer(extent Customers key ssNo){attribute string name;attribute string addr;attribute string phone;attribute integer ssNo;relationship Set<Account> ownsAcctsinverse Account::ownedBy;}class Account(extent Accounts key number){attribute integer number;attribute string type;attribute real balance;relationship Set<Customer> ownedByinverse Customer::ownsAccts}Solutions for Section 4.4Exercise 4.4.1(a)Since the relationship between customers and accounts is many-many, we should create a separate relation from that relationship-pair.Customers(ssNo, name, address, phone)Accounts(number, type, balance)CustAcct(ssNo, number)Exercise 4.4.1(d)Ther is only one attribute, but three pairs of relationships from Person to itself. Since motherOf and fatherOf are many-one, we can store their inverses in the relation for Person. That is, for each person, childrenOfMale and childrenOfFemale will indicate that persons's father and mother. The children relationship is many-many, and requires its own relation. This relation actually turns out to be redundant, in the sense that its tuples can be deduced from the relationships stored with Person. The schema:Persons(name, childrenOfFemale, childrenOfMale)Parent-Child(parent, child)Exercise 4.4.4Y ou get a schema like:Studios(name, address, ownedMovie)Since name -> address is the only FD, the key is {name, ownedMovie}, and the FD has a left side that is not a superkey.Exercise 4.4.5(a,b,c)(a) Struct Card { string rank, string suit };(b) class Hand {attribute Set theHand;};For part (c) we have:Hands(handId, rank, suit)Notice that the class Hand has no key, so we need to create one: handID. Each hand has, in the relation Hands, one tuple for each card in the hand.Exercise 4.4.5(e)Struct PlayerHand { string Player, Hand theHand };class Deal {attribute Set theDeal;}Alternatively, PlayerHand can be defined directly within the declaration of attribute theDeal. Exercise 4.4.5(h)Since keys for Hand and Deal are lacking, a mechanical way to design the database schema is to have one relation connecting deals and player-hand pairs, and another to specify the contents of hands. That is:Deals(dealID, player, handID)Hands(handID, rank, suit)However, if we think about it, we can get rid of handID and connect the deal and the player directly to the player's cards, as:Deals(dealID, player, rank, suit)Exercise 4.4.5(i)First, card is really a pair consisting of a suit and a rank, so we need two attributes in a relation schema to represent cards. However, much more important is the fact that the proposed schema does not distinguish which card is in which hand. Thus, we need another attribute that indicates which hand within the deal a card belongs to, something like:Deals(dealID, handID, rank, suit)Exercise 4.4.6(c)Attribute b is really a bag of (f,g) pairs. Thus, associated with each a-value will be zero or more (f,g) pairs, each of which can occur several times. We shall use an attribute count to indicate the number of occurrences, although if relations allow duplicate tuples we could simply allow duplicate (a,f,g) triples in the relation. The proposed schema is:C(a, f, g, count)Solutions for Section 4.5Exercise 4.5.1(b)Studios(name, address, movies{(title, year, inColor, length,stars{(name, address, birthdate)})})Since the information about a star is repeated once for each of their movies, there is redundancy. To eliminate it, we have to use a separate relation for stars and use pointers from studios. That is: Stars(name, address, birthdate)Studios(name, address, movies{(title, year, inColor, length,stars{*Stars})})Since each movie is owned by one studio, the information about a movie appears in only one tuple of Studios, and there is no redundancy.Exercise 4.5.2Customers(name, address, phone, ssNo, accts{*Accounts})Accounts(number, type, balance, owners{*Customers})Solutions for Section 4.6Exercise 4.6.1(a)We need to add new nodes labeled George Lucas and Gary Kurtz. Then, from the node sw (which represents the movie Star Wars), we add arcs to these two new nodes, labeled direc tedBy and producedBy, respectively.Exercise 4.6.2Create nodes for each account and each customer. From each customer node is an arc to a node representing the attributes of the customer, e.g., an arc labeled name to the customer's name. Likewise, there is an arc from each account node to each attribute of that account, e.g., an arc labeled balance to the value of the balance.To represent ownership of accounts by customers, we place an arc labeled owns from each customer node to the node of each account that customer holds (possibly jointly). Also, we placean arc labeled ownedBy from each account node to the customer node for each owner of that account.Exercise 4.6.5In the semistructured model, nodes represent data elements, i.e., entities rather than entity sets. In the E/R model, nodes of all types represent schema elements, and the data is not represented at all. Solutions for Section 4.7Exercise 4.7.1(a)<STARS-MOVIES><STAR starId = "cf" starredIn = "sw, esb, rj"><NAME>Carrie Fisher</NAME><ADDRESS><STREET>123 Maple St.</STREET><CITY>Hollywood</CITY></ADDRESS><ADDRESS><STREET>5 Locust Ln.</STREET><CITY>Malibu</CITY></ADDRESS></STAR><STAR starId = "mh" starredIn = "sw, esb, rj"><NAME>Mark Hamill</NAME><ADDRESS><STREET>456 Oak Rd.<STREET><CITY>Brentwood</CITY></ADDRESS></STAR><STAR starId = "hf" starredIn = "sw, esb, rj, wit"><NAME>Harrison Ford</NAME><ADDRESS><STREET>whatever</STREET><CITY>whatever</CITY></ADDRESS></STAR><MOVIE movieId = "sw" starsOf = "cf, mh"><TITLE>Star Wars</TITLE><YEAR>1977</YEAR></MOVIE><MOVIE movieId = "esb" starsOf = "cf, mh"><TITLE>Empire Strikes Back</TITLE><YEAR>1980</YEAR></MOVIE><MOVIE movieId = "rj" starsOf = "cf, mh"><TITLE>Return of the Jedi</TITLE><YEAR>1983</YEAR></MOVIE><MOVIE movieID = "wit" starsOf = "hf"><TITLE>Witness</TITLE><YEAR>1985</YEAR></MOVIE></STARS-MOVIES>Exercise 4.7.2<!DOCTYPE Bank [<!ELEMENT BANK (CUSTOMER* ACCOUNT*)><!ELEMENT CUSTOMER (NAME, ADDRESS, PHONE, SSNO)> <!A TTLIST CUSTOMERcustId IDowns IDREFS><!ELEMENT NAME (#PCDA TA)><!ELEMENT ADDRESS (#PCDA TA)><!ELEMENT PHONE (#PCDA TA)><!ELEMENT SSNO (#PCDA TA)><!ELEMENT ACCOUNT (NUMBER, TYPE, BALANCE)><!A TTLIST ACCOUNTacctId IDownedBy IDREFS><!ELEMENT NUMBER (#PCDA TA)><!ELEMENT TYPE (#PCDA TA)><!ELEMENT BALANCE (#PCDA TA)>]>Database Systems: The CompleteBookSolutions for Chapter 5Solutions for Section 5.2Exercise 5.2.1(a)PI_model( SIGMA_{speed >= 1000} ) (PC)Exercise 5.2.1(f)The trick is to theta-join PC with itself on the condition that the hard disk sizes are equal. That gives us tuples that have two PC model numbers with the same value of hd. However, these two PC's could in fact be the same, so we must also require in the theta-join that the model numbers be unequal. Finally, we want the hard disk sizes, so we project onto hd.The expression is easiest to see if we write it using some temporary values. We start by renaming PC twice so we can talk about two occurrences of the same attributes.R1 = RHO_{PC1} (PC)R2 = RHO_{PC2} (PC)R3 = R1 JOIN_{PC1.hd = PC2.hd AND PC1.model <> PC2.model} R2R4 = PI_{PC1.hd} (R3)Exercise 5.2.1(h)First, we find R1, the model-speed pairs from both PC and Laptop. Then, we find from R1 those computers that are ``fast,'' at least 133Mh. At the same time, we join R1 with Product to connect model numbers to their manufacturers and we project out the speed to get R2. Then we join R2 with itself (after renaming) to find pairs of different models by the same maker. Finally, we get our answer, R5, by projecting onto one of the maker attributes. A sequence of steps giving the desired expression is: R1 = PI_{model,speed} (PC) UNION PI_{model,speed} (Laptop)R2 = PI_{maker,model} (SIGMA_{speed>=700} (R1) JOIN Product)R3 = RHO_{T(maker2, model2)} (R2)R4 = R2 JOIN_{maker = maker2 AND model <> model2} (R3)R5 = PI_{maker} (R4)Exercise 5.2.2Here are figures for the expression trees of Exercise 5.2.1 Part (a)Part (f)Part (h). Note that the third figure is not really a tree, since it uses a common subexpression. We could duplicate the nodes to make it a tree, but using common subexpressions is a valuable form of query optimization. One of the benefits one gets from constructing ``trees'' for queries is the ability to combine nodes that represent common subexpressions.Exercise 5.2.7The relation that results from the natural join has only one attribute from each pair of equated attributes. The theta-join has attributes for both, and their columns are identical.Exercise 5.2.9(a)If all the tuples of R and S are different, then the union has n+m tuples, and this number is the maximum possible.The minimum number of tuples that can appear in the result occurs if every tuple of one relation also appears in the other. Surely the union has at least as many tuples as the larger of R and that is, max(n,m) tuples. However, it is possible for every tuple of the smaller to appear in the other, so it is possible that there are as few as max(n,m) tuples in the union.Exercise 5.2.10In the following we use the name of a relation both as its instance (set of tuples) and as its schema (set of attributes). The context determines uniquely which is meant.PI_R(R JOIN S) Note, however, that this expression works only for sets; it does not preserve the multipicity of tuples in R. The next two expressions work for bags.R JOIN DELTA(PI_{R INTERSECT S}(S)) In this expression, each projection of a tuple from S onto the attributes that are also in R appears exactly once in the second argument of the join, so it preserves multiplicity of tuples in R, except for those thatdo not join with S, which disappear. The DELTA operator removes duplicates, as described in Section 5.4.R - [R - PI_R(R JOIN S)] Here, the strategy is to find the dangling tuples of R and remove them.Solutions for Section 5.3Exercise 5.3.1As a bag, the value is {700, 1500, 866, 866, 1000, 1300, 1400, 700, 1200, 750, 1100, 350, 733}. The order is unimportant, of course. The average is 959.As a set, the value is {700, 1500, 866, 1000, 1300, 1400, 1200, 750, 1100, 350, 733}, and the average is 967. H3>Exercise 5.3.4(a)As sets, an element x is in the left-side expression(R UNION S) UNION Tif and only if it is in at least one of R, S, and T. Likewise, it is in the right-side expressionR UNION (S UNION T)under exactly the same conditions. Thus, the two expressions have exactly the same members, and the sets are equal.As bags, an element x is in the left-side expression as many times as the sum of the number of times it is in R, S, and T. The same holds for the right side. Thus, as bags the expressions also have the same value.Exercise 5.3.4(h)As sets, element x is in the left sideR UNION (S INTERSECT T)if and only if x is either in R or in both S and T. Element x is in the right side(R UNION S) INTERSECT (R UNION T)if and only if it is in both R UNION S and R UNION T. If x is in R, then it is in both unions. If x is in both S and T, then it is in both union. However, if x is neither in R nor in both of S and T, then it cannot be in both unions. For example, suppose x is not in R and not in S. Then x is not in R UNION S. Thus, the statement of when x is in the right side is exactly the same as when it is in the left side: x is either in R or in both of S and T.Now, consider the expression for bags. Element x is in the left side the sum of the number of times it is in R plus the smaller of the number of times x is in S and the number of times x is in T. Likewise, the number of times x is in the right side is the smaller ofThe sum of the number of times x is in R and in S.The sum of the number of times x is in R and in T.A moment's reflection tells us that this minimum is the sum of the number of times x is in R plus the smaller of the number of times x is in S and in T, exactly as for the left side.Exercise 5.3.5(a)For sets, we observe that element x is in the left side(R INTERSECT S) - T。
C Primer Plus第6版编程练习答案(已下载)
Chapter 2 Programming Exercises欧阳学文PE 2‐1/* Programming Exercise 21 */#include<stdio.h> intmain(void){ printf("GustavMahler\n");printf("Gustav\nMahler\n");printf("Gustav ");printf("Mahler\n");return 0;}PE 2‐3/* Programming Exercise 23 */#include<stdio.h> intmain(void){ int ageyears; /* age inyears */ int agedays; /*age in days *//* large ages may require the longtype */ ageyears = 101; agedays = 365 * ageyears;printf("An age of %d years is %d days.\n", ageyears, agedays); return 0;}PE 2‐4/* Programming Exercise 24 */#include<stdio.h>voidjolly(void);voiddeny(void);intmain(void){ jolly();jolly();jolly();deny();return0; }void jolly(void){printf("For he's a jolly good fellow!\n"); }void deny(void){printf("Which nobody can deny!\n"); }PE 2‐6/* Programming Exercise 26 */#include<stdio.h> intmain(void){ inttoes;toes =10;printf("toes = %d\n", toes);printf("Twice toes = %d\n", 2 * toes);printf("toes squared = %d\n", toes * toes);return 0;}/* or create two more variables, set them to 2 * toes and toes * toes */PE 2‐8/* Programming Exercise 28 */#include<stdio.h>voidone_three(void); voidtwo(void); intmain(void){printf("startingnow:\n");one_three();printf("done!\n");return 0;}void one_three(void){printf("one\n");two();printf("three\n");}void two(void){printf("two\n");}Chapter 3 Programming Exercises PE 3‐2/* Programming Exercise 32 */#include<stdio.h> intmain(void){intascii;printf("Enter an ASCII code: "); scanf("%d", &ascii);printf("%d is the ASCII code for %c.\n", ascii, ascii); return 0;}PE 3‐4/* Programming Exercise 34 */#include<stdio.h> intmain(void){ float num;printf("Enter a floatingpoint value: "); scanf("%f", &num);printf("fixedpointnotation: %f\n", num);printf("exponentialnotation: %e\n", num); printf("p notation: %a\n", num); return 0;}PE 3‐6/* Programming Exercise 36 */#include<stdio.h> intmain(void){float mass_mol = 3.0e23; /* mass of watermolecule in grams */ float mass_qt = 950; /*mass of quart of water in grams */ float quarts;float molecules;printf("Enter the number of quarts of water: ");scanf("%f", &quarts);molecules = quarts * mass_qt / mass_mol;printf("%f quarts of water contain %e molecules.\n", quarts, molecules); return 0;}Chapter 4 Programming ExercisesPE 4‐1/* Programming Exercise 41 */#include<stdio.h> intmain(void){ charfname[40];charlname[40];printf("Enter your first name: "); scanf("%s", fname); printf("Enteryour last name: ");scanf("%s", lname);printf("%s, %s\n", lname, fname); return 0;}PE 4‐4/* Programming Exercise 44 */ #include<stdio.h> intmain(void){ floatheight;charname[40];printf("Enter your height in inches: "); scanf("%f",&height); printf("Enter yourname: "); scanf("%s", name);printf("%s, you are %.3f feet tall\n", name, height / 12.0);return0;}PE 4‐7/* Programming Exercise 47 */#include<stdio.h>#include<float.h> intmain(void){ float ot_f = 1.0/ 3.0; doubleot_d = 1.0 / 3.0;printf(" float values:");printf("%.4f %.12f %.16f\n", ot_f, ot_f, ot_f); printf("double values: ");printf("%.4f %.12f %.16f\n", ot_d,ot_d, ot_d);printf("FLT_DIG: %d\n", FLT_DIG); printf("DBL_DIG: %d\n",DBL_DIG); return 0;}Chapter 5 Programming Exercises PE 5‐1/* Programming Exercise 51 */#include<stdio.h> intmain(void){ const intminperhour = 60;int minutes, hours,mins;printf("Enter the number of minutes to convert: "); scanf("%d", &minutes); while (minutes > 0 ){ hours = minutes/ minperhour; mins =minutes % minperhour;printf("%d minutes = %d hours, %d minutes\n", minutes, hours, mins); printf("Enter next minutes value (0 to quit): "); scanf("%d", &minutes);}printf("Bye\n");return0;}PE 5‐3/* Programming Exercise 53 */#include<stdio.h> intmain(void){ const intdaysperweek = 7;int days, weeks,day_rem;printf("Enter the number ofdays: "); scanf("%d", &days);while (days > 0){ weeks = days /daysperweek; day_rem= days % daysperweek;printf("%d days are %d weeks and %ddays.\n", days, weeks, day_rem);printf("Enter the number of days (0 or less to end): "); scanf("%d", &days);}printf("Done!\n");return 0;}PE 5‐5/* Programming Exercise 55*/ #include <stdio.h>int main(void) /* finds sum of first n integers */{int count,sum;int n;printf("Enter the upperlimit: "); scanf("%d", &n);count = 0;sum = 0;while (count++ < n)sum = sum + count;printf("sum = %d\n",sum); return 0;}PE 5‐7/* ProgrammingExercise 57 */#include <stdio.h>voidshowCube(double x);int main(void) /* finds cube of entered number */ { double val;printf("Enter a floatingpointvalue: "); scanf("%lf", &val);showCube(val); return 0; }void showCube(double x){printf("The cube of %e is %e.\n", x, x*x*x );}Chapter 6 Programming ExercisesPE 6‐1/* pe61.c *//* this implementation assumes the character codes */ /* are sequential, as they are in ASCII. */#include <stdio.h>#define SIZE 26 intmain( void ) { charlcase[SIZE]; int i;for (i = 0; i < SIZE;i++) lcase[i] = 'a'+ i; for (i = 0; i <SIZE; i++)printf("%c", lcase[i]);printf("\n");return 0;}PE 6‐3/* pe63.c *//* this implementation assumes the character codes */ /* are sequential, as they are in ASCII. */#include<stdio.h> intmain( void ){ char let= 'F';char start;char end;for (end = let; end >= 'A'; end) {for (start = let; start >= end; start) printf("%c", start); printf("\n");}return0;}PE 6‐6/* pe66.c */#include<stdio.h> intmain( void ){ int lower,upper, index; intsquare, cube;printf("Enter startinginteger: "); scanf("%d",&lower); printf("Enterending integer: ");scanf("%d", &upper);printf("%5s %10s %15s\n", "num", "square", "cube"); for (index = lower;index <= upper; index++){ square =index * index;cube = index * square;printf("%5d %10d %15d\n", index, square, cube); }return0;}PE 6‐8/* pe68.c */#include<stdio.h> intmain( void ){ double n, m;doubleres;printf("Enter a pair of numbers: ");while (scanf("%lf %lf", &n, &m) == 2){res = (n m) / (n * m);printf("(%.3g %.3g)/(%.3g*%.3g) = %.5g\n", n, m, n, m, res); printf("Enter next pair (nonnumeric to quit): ");}return 0;}PE 6‐11/* pe611.c */#include<stdio.h>#defineSIZE 8 intmain( void ){ intvals[SIZE];int i;printf("Please enter %dintegers.\n", SIZE); for (i = 0; i <SIZE; i++) scanf("%d",&vals[i]);printf("Here, in reverse order, are the values you entered:\n"); for (i = SIZE 1; i >= 0; i) printf("%d ", vals[i]); printf("\n"); return 0;}PE 6‐13/* pe613.c *//* This version starts with the 0 power */#include<stdio.h>#defineSIZE 8 intmain( void ){inttwopows[SIZE];int i;int value = 1; /* 2 to the 0 */for (i = 0; i < SIZE; i++){ twopows[i]= value; value*= 2;}i =0;do{printf("%d ",twopows[i]);i++; } while (i <SIZE); printf("\n"); return 0;}PE 6‐14/* pe14.c *//* Programming Exercise 614 */ #include<stdio.h>#defineSIZE 8 intmain(void){ doublearr[SIZE];doublearr_cumul[SIZE];int i;printf("Enter %d numbers:\n", SIZE);for (i = 0; i < SIZE; i++){printf("value #%d: ", i+ 1); scanf("%lf",&arr[i]); /* or scanf("%lf", arr + i); */}arr_cumul[0] = arr[0]; /* set first element */ for (i = 1; i < SIZE; i++) arr_cumul[i] = arr_cumul[i1] + arr[i]; for (i = 0; i < SIZE;i++) printf("%8g ",arr[i]); printf("\n");for (i = 0; i < SIZE; i++)printf("%8g ", arr_cumul[i]);printf("\n");return 0;}PE 6‐16/* pe616.c */#include <stdio.h>#define RATE_SIMP 0.10#defineRATE_COMP0.05 #defineINIT_AMT 100.0int main( void ){double daphne =INIT_AMT;double deidre =INIT_AMT; intyears = 0;while (deidre <= daphne){ daphne +=RATE_SIMP * INIT_AMT; deidre += RATE_COMP * deidre;++years;}printf("Investment values after %d years:\n", years); printf("Daphne: $%.2f\n", daphne); printf("Deidre: $%.2f\n", deidre); return 0;}Chapter 7 Programming Exercises PE 7‐1/* ProgrammingExercise 71 */#include <stdio.h>int main(void){ charch; intsp_ct = 0;int nl_ct =0; intother = 0;while ((ch =getchar()) != '#'){if (ch == ' ')sp_ct++; elseif (ch == '\n')nl_ct++; elseother++;}printf("spaces: %d, newlines: %d, others: %d\n", sp_ct, nl_ct, other);return0;}PE 7‐3/* Programming Exercise 73 */#include<stdio.h> intmain(void){ int n;double sumeven= 0.0; intct_even = 0;double sumodd =0.0; int ct_odd= 0;while (scanf("%d", &n) == 1 && n != 0){if (n % 2 == 0){sumeven += n;++ct_even;}else // n % 2 is either 1 or 1{sumodd += n;++ct_odd;} }printf("Number of evens: %d",ct_even); if (ct_even > 0)printf(" average: %g", sumeven / ct_even); putchar('\n');printf("Number of odds: %d",ct_odd); if (ct_odd > 0)printf(" average: %g", sumodd / ct_odd); putchar('\n');printf("\ndone\n");return0;}PE 7‐5/* Programming Exercise 75 */#include<stdio.h> intmain(void){ charch; intct1 = 0;int ct2 =0;while ((ch=getchar())!= '#'){switch(ch){case '.' : putchar('!'); ++ct1;break; case '!' :putchar('!');putchar('!');++ct2;break; default :putchar(ch);} }printf("%d replacement(s) of . with !\n", ct1); printf("%d replacement(s) of ! with !!\n", ct2);return0;}PE 7‐7// Programming Exercise 77#include <stdio.h>#define BASEPAY 10 // $10 per hour#define BASEHRS 40 // hours at basepay #define OVERTIME 1.5 // 1.5 time#define AMT1 300 // 1st rate tier#define AMT2 150 // 2st rate tier#define RATE1 0.15 // rate for 1st tier#define RATE2 0.20 // rate for2nd tier #define RATE3 0.25 //rate for 3rd tier int main(void){doublehours;double gross;double net;double taxes;printf("Enter the number of hours workedthis week: "); scanf("%lf", &hours); if(hours <= BASEHRS) gross = hours *BASEPAY; elsegross = BASEHRS * BASEPAY + (hours BASEHRS)* BASEPAY * OVERTIME; if (gross <= AMT1)taxes = gross * RATE1; else if (gross <= AMT1 + AMT2)taxes = AMT1 * RATE1 + (gross AMT1)* RATE2; elsetaxes = AMT1 * RATE1 + AMT2 * RATE2 + (grossAMT1 AMT2) * RATE3; net = gross taxes;printf("gross: $%.2f; taxes: $%.2f; net: $%.2f\n", gross, taxes, net);return0;}PE 7‐9/* Programming Exercise 79 */#include<stdio.h>#include<stdbool.h> intmain(void){intlimit;int num;int div;bool numIsPrime; // use int if stdbool.h not available printf("Enter a positive integer: ");while (scanf("%d", &limit) == 1 &&limit > 0){if (limit > 1)printf("Here are the prime numbers upthrough %d\n", limit); elseprintf("No primes.\n");for (num = 2; num <= limit;num++){for (div = 2, numIsPrime = true; (div * div) <= num; div++) if (num % div == 0) numIsPrime = false; if (numIsPrime)printf("%d is prime.\n", num);}printf("Enter a positive integer (q to quit): ");}printf("Done!\n");return 0;}PE 7‐11/* pe711.c *//* Programming Exercise 711 */#include<stdio.h>#include<ctype.h> intmain(void){const doubleprice_artichokes = 2.05; const double price_beets = 1.15; const doubleprice_carrots = 1.09; const double DISCOUNT_RATE = 0.05; const double under5 = 6.50; const double under20 = 14.00; const double base20 = 14.00; const double extralb = 0.50;charch;doublelb_artichokes = 0;double lb_beets =0; doublelb_carrots = 0;double lb_temp;double lb_total;doublecost_artichokes;doublecost_beets;doublecost_carrots;double cost_total;doublefinal_total;double discount;double shipping;printf("Enter a to buy artichokes, b for beets, "); printf("c for carrots, q to quit: "); while ((ch = getchar()) != 'q' && ch != 'Q'){ if (ch == '\n') continue; while(getchar() != '\n')continue; ch =tolower(ch);switch (ch) {case 'a' : printf("Enter pounds of artichokes: "); scanf("%lf",&lb_temp); lb_artichokes +=lb_temp; break;case 'b' : printf("Enter pounds ofbeets: "); scanf("%lf",&lb_temp); lb_beets +=lb_temp; break;case 'c' : printf("Enter pounds of carrots: "); scanf("%lf",&lb_temp); lb_carrots +=lb_temp; break;default : printf("%c is not a valid choice.\n", ch);}printf("Enter a to buy artichokes, b for beets, "); printf("c for carrots, q to quit: ");}cost_artichokes = price_artichokes *lb_artichokes; cost_beets = price_beets *lb_beets; cost_carrots = price_carrots *lb_carrots; cost_total = cost_artichokes + cost_beets + cost_carrots; lb_total =lb_artichokes + lb_beets + lb_carrots; if (lb_total <= 0) shipping = 0.0; else if (lb_total < 5.0) shipping = under5; else if (lb_total < 20) shipping = under20; else shipping = base20 + extralb *lb_total; if (cost_total > 100.0)discount =DISCOUNT_RATE * cost_total;else discount = 0.0;final_total = cost_total + shipping discount; printf("Your order:\n");printf("%.2f lbs of artichokes at $%.2f per pound:$ %.2f\n", lb_artichokes, price_artichokes, cost_artichokes);printf("%.2f lbs of beets at $%.2f per pound: $%.2f\n", lb_beets, price_beets,cost_beets); printf("%.2f lbs of carrots at $%.2f per pound: $%.2f\n", lb_carrots, price_carrots, cost_carrots); printf("Total cost of vegetables: $%.2f\n", cost_total); if (cost_total > 100)printf("Volume discount: $%.2f\n", discount); printf("Shipping: $%.2f\n", shipping); printf("Total charges:$%.2f\n", final_total); return 0; } Chapter 8 Programming Exercises PE 8‐1/* Programming Exercise 81 */#include <stdio.h>int main(void) { int ch;int ct = 0; while((ch = getchar()) != EOF)ct++;printf("%d characters read\n", ct);return0;}PE 8‐3/* Programming Exercise 83 *//* Using ctype.h eliminates need to assume consecutive coding */#include<stdio.h>#include<ctype.h> intmain(void){ int ch;unsigned long uct= 0; unsignedlong lct = 0;unsigned long oct= 0;while ((ch =getchar()) != EOF)if (isupper(ch))uct++; else if(islower(ch))lct++; elseoct++;printf("%lu uppercase characters read\n", uct); printf("%lu lowercase characters read\n", lct); printf("%lu other characters read\n", oct);return0;}/* or you coulduse if (ch >= 'A'&& ch <= 'Z')uct++;else if (ch >= 'a' && ch<= 'z') lct++; elseoct++;*/PE 8‐5/* Programming Exercise 85 *//* binaryguess.c an improved numberguesser */ /* but relies upon truthful, correct responses */#include <stdio.h>#include <ctype.h>int main(void) { inthigh = 100; int low= 1; int guess =(high + low) / 2;char response;printf("Pick an integer from 1 to 100. I will try to guess "); printf("it.\nRespond with a y if my guess is right, with");printf("\na h if it is high, and with an l if it is low.\n");printf("Uh...is your number %d?\n", guess);while ((response = getchar()) != 'y') /* get response */{if (response == '\n')continue;if (response != 'h' && response != 'l'){printf("I don't understand that response. Please enterh for\n"); printf("high, l for low, or y for correct.\n"); continue;}if (response == 'h')high = guess 1;else if (response == 'l')low = guess + 1;guess = (high + low)/ 2;printf("Well, then, is it %d?\n", guess);}printf("I knew I could doit!\n"); return 0;}PE 8‐7/* Programming Exercise 87 */#include <stdio.h>#include <ctype.h>#include <stdio.h>#define BASEPAY1 8.75 // $8.75 per hour #define BASEPAY2 9.33 // $9.33 per hour #define BASEPAY3 10.00 // $10.00 per hour #define BASEPAY4 11.20 // $11.20 per hour #define BASEHRS 40 // hours at basepay #define OVERTIME 1.5 // 1.5 time#define AMT1 300 // 1st rate tier#define AMT2 150 // 2st rate tier#define RATE1 0.15 // rate for 1st tier #define RATE2 0.20 // ratefor 2nd tier #define RATE3 0.25// rate for 3rd tier int getfirst(void);void menu(void); int main(void){ doublehours;doublegross;double net;doubletaxes;double pay;charresponse;menu();while ((response = getfirst()) != 'q'){if (response == '\n') /* skip over newlines */ continue;response = tolower(response); /* accept A as a, etc.*/ switch (response){case 'a': pay = BASEPAY1;break; case 'b': pay =BASEPAY2; break; case 'c':pay = BASEPAY3; break; case'd': pay = BASEPAY4; break;default : printf("Please enter a, b, c, d, or q.\n"); menu();continue; // go to beginning of loop}printf("Enter the number of hours workedthis week: "); scanf("%lf", &hours); if(hours <= BASEHRS) gross = hours *pay; elsegross = BASEHRS * pay + (hours BASEHRS) *pay * OVERTIME; if (gross <= AMT1)taxes = gross * RATE1; else if (gross <= AMT1 +AMT2)taxes = AMT1 * RATE1 + (gross AMT1)* RATE2; elsetaxes = AMT1 * RATE1 + AMT2 * RATE2 + (gross AMT1 AMT2) * RATE3; net = gross taxes;printf("gross: $%.2f; taxes: $%.2f; net: $%.2f\n", gross, taxes, net); menu(); }printf("Done.\n");return0;}void menu(void){printf("********************************************************""*********\n");printf("Enter the letter corresponding to the desired pay rate"" or action:\n");printf("a) $%4.2f/hr b) $%4.2f/hr\n", BASEPAY1, BASEPAY2);printf("c) $%5.2f/hr d) $%5.2f/hr\n", BASEPAY3, BASEPAY4); printf("q)quit\n");printf("*********************************************** *********""*********\n");}int getfirst(void){intch;ch = getchar();while (isspace(ch))ch = getchar();while (getchar() !='\n') continue;return ch;}Chapter 9 Programming ExercisesPE 9‐1/* Programming Exercise 91 */#include <stdio.h>double min(double,double); int main(void){double x, y; printf("Entertwo numbers (q to quit): ");while (scanf("%lf %lf", &x, &y) ==2){ printf("The smaller numberis %f.\n", min(x,y)); printf("Next two values (q to quit): ");}printf("Bye!\n");return0;}double min(double a, double b){return a < b ? a : b;}/* alternative implementation doublemin(double a, double b){ if (a< b)return a;elsereturn b;}*/PE 9‐3/* Programming Exercise 93 */#include <stdio.h>void chLineRow(char ch, int c,int r); int main(void){ char ch; int col, row; printf("Enter a character (# to quit): "); while ( (ch = getchar()) != '#') { if (ch== '\n')continue;printf("Enter number of columns and number of rows: "); if (scanf("%d %d", &col, &row) != 2) break; chLineRow(ch, col, row);printf("\nEnter next character (# to quit): "); }printf("Bye!\n");return0;}// start rows and cols at 0void chLineRow(char ch,int c, int r){int col, row;for (row = 0; row < r ; row++){for (col = 0; col < c;col++) putchar(ch);putchar('\n');}return;}PE 9‐5/* Programming Exercise 95 */#include <stdio.h>void larger_of(double *p1,double *p2); int main(void){double x, y; printf("Entertwo numbers (q to quit): ");while (scanf("%lf %lf", &x, &y) ==2){larger_of(&x, &y);printf("The modified values are %f and %f.\n", x, y); printf("Next two values (q to quit): ");}printf("Bye!\n");return0;}void larger_of(double *p1, double *p2) { if(*p1 > *p2)*p2 = *p1;else*p1 = *p2;}// alternatively:/*void larger_of(double *p1, double *p2) {*p1= *p2 = *p1 > *p2 ? *p1 : *p2; }*/PE 9‐8/* Programming Exercise 98*/ #include <stdio.h>double power(double a, int b); /* ANSI prototype */ int main(void) { double x,xpow; int n; printf("Enter a number andthe integer power"); printf(" to which\nthe number will be raised. Enter q"); printf(" toquit.\n"); while (scanf("%lf%d", &x, &n)== 2){ xpow = power(x,n); /* function call */ printf("%.3g to the power %dis %.5g\n", x, n, xpow); printf("Enter nextpair of numbers or q to quit.\n");} printf("Hope you enjoyed this powertrip bye!\n"); return 0;} double power(double a, int b) /* function definition */{ doublepow = 1;int i; if(b == 0){ if (a== 0)printf("0 to the 0 undefined; using 1 as thevalue\n"); pow = 1.0; } else if (a == 0) pow = 0.0; else if (b > 0) for(i = 1; i <= b;i++) pow *= a; else /* b < 0 */ pow = 1.0 / power(a, b);return pow; /* return the value of pow */ }PE 9‐10/* Programming Exercise 910 */#include <stdio.h> voidto_base_n(int x, int base); intmain(void) { int number; int b;int count; printf("Enter aninteger (q to quit):\n"); while(scanf("%d", &number) == 1){ printf("Enter numberbase (210): "); while ((count= scanf("%d", &b))== 1&& (b < 2 || b > 10)){printf("base should be in the range 210: ");} if(count != 1)break;。
Chemistry_coursebook_1_Ch_1_-9_answers
HKDSE CHEMISTRY – A Modern View(Chemistry)Coursebook 1Suggested answersChapter 1 The fundamentals of chemistry PageNumber •Class Practice1•Chapter Exercise 3Chapter2 The atmosphere•Class Practice6•Chapter Exercise7Chapter 3 Oceans•Chapter Exercise9Chapter4 Rocks and minerals•Class Practice12•Chapter Exercise13●Part Exercise15 Chapter 5 Atomic structure•Class Practice17•Chapter Exercise19Chapter6 The Periodic Table•Class Practice21•Chapter Exercise22Chapter 7 Chemical bonding: ionic bonding•Class Practice24•Chapter Exercise26 Chapter8 Chemical bonding: covalent bonding•Class Practice29•Chapter Exercise31 Chapter9 Structures and properties of substances•Class Practice34•Chapter Exercise35 ●Part Exercise37Chapter 1 Fundamentals of chemistryClass PracticeA1.1(b)Food : fertilizers, insecticides, food additives(c)Housing : metals, alloys, cement, glass, plastics(d)Transport : metals, alloys, fuels, glass, plastics(e)Medicines : drugs, antibiotics, artificial hormones(f)Amusement park facilities : metals, alloys, cement, glass, plastics,semi-conductorsA1.2Phosphorus and mercury are elements. The others are not.(Note: A substance with a name consisting of two words (e.g. sodium chloride) is not an element. A substance with a name of only one word (e.g. ammonia) may or may not be an element. The only sure way is to check the name against the Periodic Table.)A1.3Sodium - silvery grey solid;Chlorine - greenish yellow gas;Sodium chloride - white solid.A1.4(a) Hydrogen, oxygen, nitrogen, iron, sulphur(b) Water, carbon dioxide, carbon monoxide, sodium chloride, iron(II) sulphide(c) Air, sea water, town gas, sodium chloride solution, wine(Other answers may be given.)A1.5(a) Chemical change(b) Physical change(c) Physical change(d) Chemical change(b) and (c) are physical changes because no new substances are formed. (a) and (d) are chemical changes because new substances are formed.A1.6(a), (b) and (e).A1.8(a) Flat-bottomed flask (l) Crucible tongs (w) Reagent bottle(b) Round-bottomed flask (m) Spatula (x) Gas syringe(c) Clamp (n) Heat-resistant mat (y) Measuring cylinder(d) Retort stand (o) Pestle (z) Beaker(e) Conical flask (p) Mortar (aa) Funnel(f) Wire gauze (q) Desiccator (bb) Plastic washbottle(g) Evaporating basin (r) Test tube holder (cc) Teat pipette(h) Tripod (s) Test tube rack (dd) Thermometer(i) Crucible (t) Test tube (ee) Watch glass(j) Pipeclay triangle (u) Boiling tube (ff) Separating funnel (k) Bunsen burner (v) Dropping bottle (gg) Glass rodChapter 1 Fundamentals of chemistryChapter Exercise1. science, observations, experiments2. substances, compositions, structures, properties, changes3. Oxygen, atmosphere4. chemically combined together, hydrogen, oxygen.5. heating, electrolysis6. mixture7. chlorine, compound8. element, compound, mixture9. retains, different10. ppearance , dour , aste , ensity , elting11. chemical12. physical13. new14. A15. B16. D17. C18. C19. D20. B21. B22. A23. D24. A25. D26. C27. B28. D29. A30. (a) A = beaker, B = test tube, C = Bunsen burner, D = wire gauze, E = tripodstand, F = heat-proof mat, G = test tube holder, H = evaporating dish(evaporating basin)(b) (i) Test tube (B).(ii) Test tube(B), test tube holder (G), Bunsen burner (C) , heat-proof mat(F).(iii) Beaker (A), tripod stand (E), wire gauze (D), Bunsen burner (C),heat-proof mat (F).31. (a) Tasteless; no smell; colourless; liquid at room conditions(b) React with iron; react with sodium(c) Water changes into steam at 100o C. / Water changes into ice at 0o C.(d) It is because no new substance is formed.(e) Iron reacts with water to form iron rust. / Sodium reacts with water to formhydrogen gas.(f) New substance (e.g. rust or hydrogen gas) is formed.32. (a) Chlorine, hydrogen, iron, mercury , oxygen, sodium and sulphur(b) An element is a pure substance that cannot be broken down into anythingsimpler by chemical methods.(c) Ammonia, sodium chloride and water(d) A compound is a pure substance made up of two or more elementschemically combined together(e) A mixture consists of two or more pure substances (elements or compounds)which have not chemically combined together.(f) Sodium chloride solution is a mixture (because a solution is a homogeneousmixture).33. (a) No. Both oxygen and hydrogen are gases at room conditions while glucoseis a solid at room conditions. Carbon is black in colour while glucose iswhite.(b) Glucose solution is a mixture. It is because there is no chemical reactiontaking place between glucose and water.(c) Glucose + oxygen → carbon dioxide + water34. Compounds and mixtures are different in a number of ways. These include:(1) Compounds have fixed chemical composition while mixtures have variablechemical composition. Examples: water and air(2) During the formation of compounds, a chemical change occurs. Newsubstances are always formed. On the other hand, a mixture is obtainedwhen different substances are physically mixed. There is no chemicalchange. No new substance is formed and the change is seldom accompaniedby energy changes. Examples: formation of water from hydrogen andoxygen, mixing of sand and sugar(3) Properties of a compound are very different from that of its constituentelements. For example, water is colourless liquid while hydrogen and oxygenare colourless gases. On the other hand, each constituent substance retainsits own properties in mixtures. For example, nitrogen and oxygen are bothcolourless gases no matter whether they are isolated or present together inthe air.(4) Separation of the constituents of a compound requires a chemical process.For example, breaking water down into the elements hydrogen and oxygenrequires a chemical process called electrolysis. On the other hand,separation of a mixture requires a physical process only. For example,separation of iron powder from a mixture just requires the use of a magnet.35. -PHYSICAL PROPERTIES of a substance are those properties that can bedetermined without the substance changing into another substance.-Examples of physical properties of a substance include colour, odour (smell) and physical state. For example water is a colourless, odourless liquid under room conditions.-CHEMICAL PROPERTIES of a substance are the chemical reactions of the substance, and the respective conditions under which each reaction takes place.-Examples of chemical properties of a substance include how fast and vigorous it reacts (i.e., its reactivity) with another substance, the condition(s) needed for it to react with other substances and what products can be produced when it reacts with other substances. For example, hydrogen reacts vigorously with oxygen (or air) only when lit with a burning splint to form water.Class PracticeA2.1(a) People in ancient times had little scientific knowledge. In fact, any visibleportion of the Earth appeared more or less flat to the eyes.(b) Satellite photos clearly show that the Earth is roughly spherical.(Other answers may be given.)A2.2atmospherecrustmantleinner coreouter coreA2.31. (a) No. (7 planets have an atmosphere.)(b) Yes.2. There is no air on the Moon.A2.4Elements Compoundsnitrogen carbon dioxideoxygen water vapourheliumneonargonkryptonxenonA2.5Helium -269Neon -246Nitrogen -196Argon -186Oxygen -183Krypton -153Xenon -109Carbon dioxide -78Chapter Exercise1. crust, mantle , core, atmosphere2. atmosphere3. nitrogen, oxygen4. fractional distillation5. liquefied6. supporter7. glowing8. A9. A 10. B 11. B 12. B 13. D14. (a) Nitrogen (b) Carbon dioxide and water vapour (c) Oxygen, argon, neon, helium, krypton, xenon (any two)15. (a) The volumes of the three gases obtained i.e. argon, nitrogen and oxygen are930 litres, 78,000 litres and 21,000 litres respectively.(b) Fractional distillation (c) No. Oxygen is the most reactive gas in air, whereas nitrogen is unreactive,which serves the good purpose of ‘diluting ’ oxygen in air. If there were more oxygen in air, metals would be oxidized and corroded faster. Things would also burn easier, so there would be a greater hazard of fire.16. (a) Fractional distillation of liquid air (b) Oxidizing (c) Physical property: colourless, odourless Chemical property: it supports combustion (d) Put a glowing splint into a test tube containing the gas to be tested. If thegas is oxygen, the splint relights.17. (a) Nitrogen and oxygen (b) Oxygen (c) copper + oxygen → copper(II) oxide (d) 50 cm 3 - 33 cm 3 = 17 cm 3(e) 33cm50cm 17⨯ 100% = 34% (f) 21% (g) The percentage of oxygen in dissolved air (34 %) is much greater than thatin the atmosphere (21 %) because oxygen is more soluble in water than nitrogen.18. -Fractional distillation of liquid air is used to separate nitrogen and oxygenfrom air.-The air is first liquefied by repeated cooling and compression.-Then the liquid air is warmed up bit by bit very slowly.-Different gases in air boil at different temperatures, so they can be collected one by one.-The one boiling off first is nitrogen (boiling point -196 ︒C). The second one to be collected is argon(boiling point -186 ︒C) /noble gas. Then oxygen gas (boiling point -183 ︒C) is collected.Chapter 3 OceansChapter Exercise1. sodium chloride (common salt), sodium, chlorine2. evaporation3. filtration, crystallization4. saturated5. boiling, condensation6. distillate, residue7. distillation8. flame test9. brilliant golden yellow10. white11. water, white, blue, blue, pink12. Brine13. hydrogen, chlorine, sodium hydroxide14. B15. C16. B17. C18. D19. A20. (a) Filtration(b)(c) Distillation(d)(e) Test for sodium ions: Flame test. The sample gives a brilliant golden yellow flame in the flame test if sodiumions are present.Test for chloride ions: Silver nitrate testAdd silver nitrate solution to the sample, followed by excess dilute nitric acid. Theappearance of a white precipitate indicates the presence of chloride ions.21. His conclusion is not justified. He should add the white-powder to distilled waterand stir well, then filter and evaporate the filtrate to dryness by heating, and see if any solid is left.22. (a) This is because some metal ions can produce a characteristic coloured lightwhen they are heated strongly.(b) (1) Moisten a clean platinum wire with concentrated hydrochloric acid.(2) Dip the platinum wire into a crushed sample of the salt (or solution) tobe tested.(3) Heat the platinum wire with the sample strongly in a non-luminousflame.(4) Observe the colour of the flame at the wire and identify the metal ionspresent.(c) Potassium ions: lilac; calcium ions: brick red; copper (II) ions: bluish green.23. (a) It was not a suitable method because the liquid may be unclean, harmful oreven poisonous.(b) Flame test.(c) To show the presence of chloride ions, acidified silver nitrate solution isadded to the sample. If chloride ions are present, a white precipitate will be formed.(d) To show the presence of water, a few drops of the liquid are added toanhydrous copper(II) sulphate.The powder changes from white to blue if water is present.Alternatively, add a few drops of the liquid to dry cobalt chloride test paper. The paper changes from blue to pink if water is present. thermometerdelivery tubeclampboiling tube sodium chloridesolutionheatanti-bumping granulereceiver test tubewater pure water(e) He could not be sure that the liquid was sea water. Even if the tests showedthat sodium ions, chloride ions and water were present, the liquid might notnecessarily be sea water. For example, it might be just a sodium chloridesolution, without any other salts naturally present in sea water.24. (a) Electrolysis means ‘decomposition by electricity’.(b) Chlorine, hydrogen and sodium hydroxide.(c) Chlorine − water sterilization, manufacture of bleach, etc.Hydrogen − production of margarine, as rocket fuel, etc.Sodium hydroxide − manufacture of soap, extraction of aluminium, etc. 25. -Sea water is an important source of common salt (sodium chloride) which hasmany uses.-By the electrolysis of sea water, useful products, hydrogen, chlorine and sodium hydroxide are obtained. These products can be used to manufacture a lot of useful chemicals.-Hydrogen can be used to produce ammonia.- Chlorine can be used to produce bleach.- Sodium hydroxide can be used to produce soap.Class PracticeA4.1heat calcium oxide + carbon dioxideStep 1: calcium carbonate −−−−→Step 2: calcium oxide + water → calcium hydroxideStep 3: calcium hydroxide + water → calcium hydroxide solution (limewater) Step 4: calcium hydroxide solution (limewater) + carbon dioxide→ calcium carbonate + waterA4.2calcium carbonate + nitric acid → calcium nitrate + carbon dioxide + waterChapter Exercise1. mineral, a mixture of minerals2. crystalline, chemical3. extraction4. ore, aluminium5. haematite, carbon (or coke)6. chalk, marble7. Neutralizing, building material, cement (or other acceptable answers)8. Weathering9. Erosion10. PhysicalChemical11. uicklime, calcium oxide.12. acids, carbon dioxide13. milky14. iron + carbon dioxide15. aluminium + oxygen16. carbonic acid17. calcium hydroxide + heat18. calcium hydrogencarbonate19. calcium oxide + carbon dioxide20. calcium carbonate (white solid) + water21. calcium chloride + carbon dioxide + water22. B23. D24. D25. C26. A27. B28. D29. C30. C31. B32. (a) (1) Both react with acid to give out carbon dioxide.(2) Both are decomposed on strong heating.(b) (1) Neutralizing acidic soil and lakes affected by acid rain.(2) As a raw material to make glass by heating with sand and sodiumcarbonate.(3) As a raw material to make cement by heating with clay. (or any otherpossible answers)33. (a) Weathering is the slow process in which exposed rocks are broken downinto smaller pieces.(b) Physical weathering and chemical weathering.(c) It is because carbon dioxide in air dissolves slightly in rainwater, formingcarbonic acid. Carbonic acid can attack rocks.(d) Calcium hydrogencarbonate(e) calcium carbonate + carbonic acid → calcium hydrogencarbonate34. (a) Calcium carbonate(b) calcium carbonate −−−−→− heat strongcalcium oxide + carbon dioxide (c)(d) When the gas is passed through limewater for a few seconds, the limewater turns milky.35.(a) (i) Calcium oxide(ii) Calcium hydroxide(iii) Calcium hydroxide solution(b) (i) calcium carbonate −−→−heat calcium oxide + carbon dioxide(ii) calcium carbonate + hydrochloric acid → calcium chloride + carbon dioxide + water(iii) calcium oxide + water −→ calcium hydroxide(iv) carbon dioxide + calcium hydroxide solution−→ calcium carbonate + water (c) The rock fizzes (colourless gas is given out).heat limewaterPart I Planet earthPart Exercise1. C2. C3. A4. A5. C6. A7. B8. C9. A10. C11. D12. D13. C14. B15. A16. C17. B18. C19. B20. (a) Hydrogen ― as fuelOxygen ― in breathing aids (or any other possible answers)(b) No. Oxygen and hydrogen inside the container mix to form a gaseousmixture. All mixtures are impure substances.(c) Water(d) Yes. Water is a compound, and a single compound when existing alone is apure substance.21. (a) This conclusion is valid. The brick red colour in the flame test indicates thepresence of calcium, and the white precipitate formed when acidified silvernitrate solution is added indicates the presence of chloride.(b) This conclusion is invalid. The bubbles formed when acid was added maynot be carbon dioxide.(c) Conclusion (a) cannot be disproved. To test the validity of conclusion (b),pass the gas formed into limewater. If the limewater turns milky, the gas iscarbon dioxide, then the conclusion is valid. If the limewater doesn’t turnmilky, the conclusion is invalid.(d) The only validity of this statement is that the sample is a mixture containingcalcium chloride. Even carbonate is shown to be present, the tests carriedout are insufficient to rule out the possibility of other substances present inthe sample.22.(a) X : carbon dioxide; Y : water; Z : carbon dioxide.(b) calcium carbonate −−→−heat calcium oxide + carbon dioxideThe limestone cracks and makes a cracking noise.(c) calcium oxide + water → calcium hydroxide + heatA lot of heat is produced, with the possible production of some steamy vapour. The white solid turns into a paste.(d) calcium hydroxide + carbon dioxide → calcium carbonate + waterThe calcium hydroxide solution (limewater) turns milky.(e) This is the limewater test for carbon dioxide.23. (a) Refer to Coursebook 1 page 69.(b) Refer to Coursebook 1 page 70.(c) Frost action is a physical weathering process. This is because no newsubstances are formed during the process. Action of carbonic acid is a chemical weathering process. This is because carbonic acid changes calcium carbonate to a new substance, calcium hydrogencarbonate.(d) When excess of carbon dioxide is bubbled in, soluble calciumhydrogencarbonate is formed.Chapter 5 Atomic structureClass PracticeA5.1They are the only two liquid elements.A5.21. (a) Only an element can be classified as a metal or non-metal. Water is not anelement.(b) Non-metal.(c) Metal.2. (a) Mercury. All are metals. Mercury is a liquid, while the others are solids atroom conditions.(b) Sulphur. Sulphur is a non-metal, while the others are metals.(c) Iodine. All are non-metals. Iodine is a solid, while the others are gases atroom conditions.(d) Graphite. All are non-metals. Graphite conducts electricity, while the othersare non-conductors of electricity.A5.3(a) (i) Mg(ii)Ag(iii) Na(b)(i) Ar,(ii) He(iii) Ne(c) (i) fluorine(ii) bromine(iii) mercuryA5.4(a) 118(b) Br(c) N(d) The element copper or a copper atom.A5.5(a) The commonest type of hydrogen atom.(b) 91 electrons. Number of neutrons cannot be predicted.(c) It is not an atom. The numbers of protons and electrons are not equal.A5.6A magnesium atom would be changed to a chlorine atom.A5.71. (a) silver(b) silver(c) silver2. (a) Aluminium(b) Al1327(c) (i) 13(ii) 13(iii) 27 - 13 = 14A5.8(a) 3(b) O816(16O, or oxygen-16)A5.9(a) 37(b) 35(c) 4(d) 238(e) We cannot tell from the given data.(The mass number is not given.)A5.10(a) Relative atomic mass of sodium= mass number of the only type of sodium atom = 23(b) Relative atomic mass of neon=10010229020⨯+⨯= 20.2A5.11(a) (b)(c) (d)A5.12(a) 17(b) (i) 2,8,7(ii)Chapter 5 Atomic structureChapter Exercise1. physical2. bromine, mercury3. metals, non-metals4. metals, non-metals, graphite5. ymbol6. smallest part7. element8. atoms9. nucleus, neutrons, nucleus, electrons10. positively, negatively, neutral11. protons12. mass number13. same, different14. carbon-1215. weighted average, relative isotopic16. shells17. electronic arrangement (electronic configuration)18. B19. D20. D21. B22. C23. D24. C25. D26. (a) True. This is because there is no gaseous metal or semi-metal at roomconditions.(b) False. This is because mercury is a liquid metal at room conditions.(c) False. This is because carbon (graphite) is a non-metal which can conductelectricity. / This is because semi-metals cannot conduct electricity bythemselves.(d) False. This is because some metals (e.g. sodium) are soft.(e) True. This is because metals are silvery white, golden or brown in colour.No metal is red in colour.27. (a) The mass number of an atom is the sum of the number of protons andneutrons in the atom.(b) The atomic number of an atom is the number of protons in the atom.(c) Isotopes are different atoms of the same element, with the same number ofprotons (and electrons) but different numbers of neutrons.(d) Atom Number of protons Number of neutrons Electronic configuration105B 5 5 2, 3 115B 5 6 2, 3 (e) 10.810080112010=+⨯⨯ 28. (a) Q and R(b) Carbon(c) Carbon-13 and carbon-14(d) 135P , 136Q , 146R , 147S29. (a)AtomAtomic no. Mass no. Number of Electronic arrangement protons neutrons electrons (a)35Cl 17 35 17 18 17 2, 8, 7 (b)17O 8 17 8 9 8 2, 6 (c) 40Ar 18 40 18 22 18 2, 8, 8(b)(c) Neon(d) Argon is very unreactive.30. - Elements can be classified according to their physical states . For example, atroom temperature, hydrogen and oxygen are gases; bromine and mercury are liquids; carbon and iodine are solids.- Elements can also be classified into metals and non-metals. A few elementshave properties in between those of metals and non-metals. They are classified as semi-metals.- Examples of metals include sodium and mercury; examples of non-metalsinclude bromine and hydrogen; examples of semi-metals include boron and silicon.Class PracticeA6.1(a) Period 7, Group II; alkaline earth metals.(b) Radium.(c) Yes. Radium is a metal (all metals conduct electricity).A6.2Element X: MetalElement Y: Non-metalElement Z: We cannot tell from the given data as elements in Group IV can be a metal, non-metal or semi-metal.A6.3(a) 2, 8, 8, 2.(b) Yes, it is a metal.(c) (ii).A6.4(a) Yes. By knowing the chemical properties of familiar elements in the same groupand the group trend, predictions about the unfamiliar element can be made. (b) Astatine: D; strontium: AChapter Exercise1. electrons, outermost2. ascending, atomic numbers3. period, group, eight,4. period number, outermost5. metals, semi-metals, non-metals6. chemical7. 1, 1, increases8. 7, halogens, decreases9. 8, noble gases10. B11. B12. D13. C14. C15. C16. C17. D18.19. (a) 2(b) They all have two electrons in the outermost shell.(c) Increase down the Group.(d) (i) Beryllium reacts very slowly with water.(ii) Barium reacts vigorously with water.(e) Barium is more reactive than calcium. It should be stored under paraffin.20. (a) Magnesium, silicon, chlorine. They are in Period 3.(b) Lithium, rubidium, caesium. They are in Group I.(c) Iron, copper(d) Caesium(e) Fluorine(f) Silicon(g) Helium(h) Helium, fluorine, chlorine(i) Fluorine, chlorine21. (a) Group II(b) Alkaline earth metals(c) Strontium has 2 outermost shell electrons.(d) Strontium is a silvery white solid at room conditions.(e) Strontium reacts with cold water more readily than calcium does andcolourless gas bubbles are given off. This is because the reactivity of GroupII elements will increase down the group.22. - In the modern Periodic Table, elements are arranged in ascending order ofatomic number.- The elements are arranged in periods and groups of the Periodic Table.A horizontal row of elements is called a period while a vertical column ofelements is called group.- Period number = number of occupied electron shellsGroup number = number of electrons in outermost shell- Elements within the same group of the Periodic Table have similar chemical properties.- Across a period, the elements change from metals through semi-metals to non-metals.- Some of the groups have special names. Group I elements are named as alkali metals; Group II elements are named as alkaline earth metals; Group VII elements are named as halogens; Group 0 elements are named as noble gases.The elements in between Group II and Group III are called the transition elements.Chapter 7 Chemical bonding: ionic bondingClass PracticeA7.1(a) Delete ‘non-metals’.(b) Delete ‘metals’.A7.2(a) Colourless(b) Purple(c) Yellow(d) GreenA7.3(a) The cathode. Potassium ions are positively charged. They are thus attractedtowards the negative electrode (cathode).(b) No. Potassium ions are colourless.(c) A green patch would move towards the negative electrode (cathode).Chromium(III) ions are green in colour and positively charged. They are attracted towards the negative electrode.A7.4(a) (i) Aluminium atom: 2, 8, 3; aluminium ion: 2, 8(ii) Chlorine atom: 2, 8, 7; chloride ion: 2, 8, 8(b) Charge on aluminium ion = +3; charge on chloride ion = -1A7.5Simple ions: H+, H-, Mn2+Polyatomic ions: NH4+, NH2-, OH-A7.6(a)(ii) At-A7.7(a)(b)A7.8(a) CuCl2(b) CaS(c) Al(OH)3(d) (NH4)2CO3A7.9(a) Mg(OH)2(b) Na2O(c) PbSO4(d) K2Cr2O7A7.10(a) Calcium nitrate(b) Iron(III) chloride(c) Zinc sulphate-7-water(d) Copper(II) hydroxideChapter 7 Chemical bonding: ionic bondingChapter Exercise1. octet, duplet2. electrons, noble gas, ions3. simple, polyatomic4. cations, anions5. coloured6. electrolysis7. name, formula8. group9. minus10. ionic, ionic, calcium oxide, calcium, oxygen, Calcium (Ca2+), oxide (O2-), ionicbonds11. giant ionic structure12. B13. A14. D15. A16. C17. A18. C19. B20.21. (a) Calcium sulphate(b) Cation: calcium ion; anion: sulphate ion(c) Ionic bonding(d) CaSO4(e) The coagulant is white in colour.(g) Polyatomic ion22. (a) A: 2,5; B: 2, 8, 1; C: 2, 8, 2; D: 2, 8, 6(b) Elements A and D tend to gain electrons to attain an octet of electrons.(c) Elements B and C tend to lose electrons to attain an octet of electrons.(d) 4(e) B3A; B2D; C3A2; CD(f)B3A B2DC3A CD23. (a) Magnesium chloride: MgCl2; potassium chloride: KCl; sodium chloride:NaCl(b)MgCl2KClNaCl(c) Giant ionic structure24. -Consider the reaction between sodium and chlorine.A sodium atom Na has the electronic arrangement 2,8,1. It loses 1 electron toget the stable octet structure to form a Na+ ion.-A chlorine atom Cl has the electronic arrangement 2,8,7. It gains 1 electron to get the stable octet structure to form a Cl- ion.-When sodium atom reacts with a chlorine atom, the sodium atom loses 1 electron to the chlorine atom. By transfer of electron, two ions are formed.The electrostatic force between the ions is called ionic bonds and the compound is called ionic compound.electronsodium atom(Na) (loses one electron)sodium ion(Na+) chlorine ion(Cl-)transferchlorine atom(Cl)(gains one electron)。
练习题
Chapter 1 exercise1. Hard work, thrift（节约）, piety（虔诚）and sobriety（清醒）, theses were the Puritan values that dominated much of the early American writing.2. The Tenth Muse Lately Sprung Up in America is a collection of poems composed by Anne Bradstreet3. Anne Bradstreet was a Puritan poet. Her poems made such a stir(骚动) in England that she became known as the“” who appeared in America.A. Ninth MuseB. Tenth MuseC. Best MuseD. First MuseChapter 2 exercise1. The War of Independence lasted eight years till 1783.2. Thomas Paine, with his natural gift for pamphleteering（小册子作者）andrebellion, was appropriately born into an age of revolution .3. A series of sixteen pamphlets by Paine was entitled The American Crisis.4. Franklin's best writing is found in his masterpiece Autobiography.5. Franklin was the epitome(化身) [i'pitəmi] of the Enlightenment , the versatile(多才多艺的), practical embodiment(体现) of national man in the18th century.6. The most outstanding poet in America of the 18th century was Philip Freneau.7. Philip Freneau was considered as the "poet of the American Revolution."8. Except Common Sense, Paine's the other two famous works were Rights of man《人权》and The age of Reason《理性时代》.9. Eighteen-century America experienced an age of enlightenment, of reason and order like England and Europe.10. Franklin's claim to a place in literature rests chiefly on his PoorRichard’s Almanac and Autobiography.Chapter 3 exercise1. In the early nineteenth century, Washington Irving wrote The Sketch Book ,which became the first work by an American writer to win financial success on both sides of the Atlantic.2. The Romantic period in the American literary history covers the time between the end of the 18th_century to the outbreak of the Civil War . It started with the publication of Irving‟s The sketch book and ended with Whitman‟s leaves of Grass. This period is also called_the American Renaissance.3. Irving's The Sketch Book is a collection of essays, sketches and tales, of which the most famous and frequently anthologized([æn'θɔlədʒaiz] 把…收入选集) are Rip Van Winkle and The legend of Sleepy Hollow.4. The Transcendental Club often met at Emerson‟s Concord home.5. Emersonian Transcendentalism is actually a philosophical school which absorbed some ideological concerns of American Puritanism and European Romanticism.6. Washington Irving was regarded as Father of the American short stories.7. Irving also wrote two biographies, one is The Life of Oliver Goldsmith, and the other is Life of Washington.8. Cooper's novel The Spy was a rousing tale about espionage（间谍活动）against the British during the Revolutionary War.9. The central figure in the Leather stocking Tales is Natty Bumppo, who goes by the various names of Leather stocking, Deer slayer, Pathfinder and Hawkeye.10. A superb（极好的）book Walden came out of Thoreau's two-yearexperiment at Walden Pond.11. From Thoreau's Concord jail experience，came his famous essay ___Civil Disobedience_.12. Hester Prynne is the heroine（女英雄, 女主角）in Hawthorne's novel TheScarlet Letter.13. Melville's novel Moby Dick is a tremendous chronicle of a whalingvoyage in pursuit of a seemingly supernatural white whale.14. Ishmael is the narrator in Moby-Dick.15._ Edgar Allan Poe _ can somewhat be called "the Father of the Americandetective story".Romantic Period Exercise1. The Romantic Period of American literature started with the publication of Washington Irving‟s ___________ and ended with Whitman‟s Leaves of Grass.A. The Sketch BookB. Tales of a TravelerC. The AlhambraD. A History of New York2. Washington Irving‟s social conservation and literary for the past is revealed to some extent, in his famous story_____________.A. “The Legend of Sleepy Hollow”B. Rip Van WinkleC. The Custom-HouseD. The Birthmark3. The period before the American Civil War is generally referred to as_________.A. The naturalist PeriodB. The Modern PeriodC. The Romantic PeriodD. the Realistic period4. In the following works, which signs the beginning of the American literature?A. The Sketch BookB. Leaves of GrassC. Leather stocking TalesD. Adventures of Huckleberry Finn5. In the history of literature, Romanticism is regarded as _________.A. the thought that designates（标明）a literary and philosophical theorywhich tends to see the individual as the very center of all life and allexperienceB. the orientation that emphasizes those features which men have incommonC. the modes of thinkingD. the thought that designates man as a social animalChapter 5 exercise1. First World War stands as a great dividing line between the nineteenth century and the contemporary American literature.2.Hemingway became the spokesman for what Gertrude Stein had called "the lost generation".3. Fitzgerald's The Great Gatsby is set in the Jazz Age.4. William Faulkner wrote about the disintegration（瓦解）of the old social system in the American Southern States, and its effect on the lives of modem people, both black and white.5. Pound was the leader of a new movement in poetry which he calledthe“imagism movement.6. Ezra Pound's major work of poetry is the long poem called The Cantos.7. "After Apple-Picking" is a well-known poem written by Robert Frost.8. William Faulkner's works mainly concern the American South.9. Wallace Stevens was successful in two fields of activity which did not seem compatible（可以并存的, 相容的, 协调的）with one another: he was a very successful businessman and a very remarkable contemporary poet at the same time.10. In the novel The Old Man and the Sea, Hemingway portrayed an oldfisherman named Santigago, who shows triumphant even in defeat. 11. In the same way that Fitzgerald's "Tales of the Jazz Age" became thesymbol for an age, Hemingway's novel The Sun Also Rises painted the image of a whole generation, the lost generation.1. ___is often acclaimed literary spokesman of the Jazz Age.A. Ernest HemingwayB. F. Scott FitzgeraldC. William FaulknerD. Ezra Pound2. is Hemingway's first true novel in which he depicts a vivid portrait of "The Lost Generation".A. The Sun Also RisesB. A Farewell to ArmsC. In Our TimeD. For Whom the Bell Tolls3. In a tragic sense, is a representation of life as a struggle against unconquerable forces in which only a partial victory is possible. A. For Whom the Bell Tolls B. In Our TimeC. The Old Man and the SeaD. A Farewell to Arms4. Tender Is the Night is a by Fitzgerald.A. short storyB. novellaC. poemD. novel5. Hemingway's writing style, together with his theme and the hero, is greatly and permanently influenced by his experiencesA. in his childhoodB. in the warC. in AmericaD. in Africa6. The following writers were awarded Nobel Prize for literature exceptA. W'dliam FaulknerB.F. Scott FitzgeraldC. John SteinbeckD. Ernest Hemingway7. "Two roads diverged in a yellow wood and sorry I could not travelboth..."In the above two lines of Robert Frost's The Road Not Taken, the poet, by implication, was referring toA. a travel experienceB. a marriage decisionC. a middle-age crisisD. one's course of life8. The American "Thirties", lasted from the Crash, through the ensuing Great Depression, until the outbreak of the Second World War 1939. This was a periodA. povertyB. bleaknessC. important social movementsD. a new social consciousnessE. all of the above9. The Fitzgeralds lived so extravagantly(挥霍无度地) that they frequently spent more money than Fitzgerald earned for parties, liquor, entertaining their friends and travelling. It was this living style that nicknamed the decade of the 1920s asA. The Roaring TwentiesB. The Jazz AgeC. The Dollar DecadeD. all of the above10. In Faulkner's The Sound and the Fury, he used a technique called inwhich the whole story was told through the thoughts of one character.A. stream of consciousnessB. imagismC. symbolismD. naturalism11. Who is the author of the work: "The Grapes of Wrath"?A. John Steinbeck.B. Eugene O'Neil.C. E Scott Fitzgerald.D. Theodore Dreiser.realism exercise•1. The Age of Realism in the literary history of the United States refers to the period from 1865to 1918.•2. Stylistically, Henry James' fiction is characterized by . •A. highly refined language B. ordinary American speech•C. short, clear sentences D. abundance of local images•3. is not a novel by Henry James dealing with the international theme.•A. What Maisie Knows B. The Wings of the Dove•C. The Ambassadors D. The Golden Bowl•Answer: D A A•4. Who exerts the single most important influence on literary naturalism, of which Theodore Dreiser and Jack London are among the best representative writers?•A. Freud. B. Darwin C. Howells. D. Emerson.•5. Mark Twain, one of the greatest 19~ century American writers, is well known for his .•A. international theme B. waste-land imagery•C. local color D. symbolism•6. Generally speaking, all those writers with a naturalistic（自然主义的）approach to human reality tend to be .•A. transcendentalists B. idealists（理想主义;空想家）•C. pessimists（悲观主义者） D. impressionists •Answers: B C C7. Mark Twain wrote most of his literary works with alanguage.A. grandB. pompousC. simpleD. vernacular（[vəˈnækj ələ]本国语,本地话,方言2）8. Henry James experimented with many different themes in his literary career, the most influential one being .A. nothingnessB. Disillusionment（醒悟;理想破灭）C. international themeD. relationship between men and women9. Theodore Dreiser is generally regarded as one of America's .A. naturalistsB. realistsC. modernistsD. romanticistsAnswers: D C A10. Dreiser's Trilogy of Desire includes three novels. They are The Financier, The Titan andA. The StoicB. The GiantC. The TycoonD. The Genius11. The impact of Darwin's evolutionary theory on the American thought and the influence of the nineteenth-century French literature on the American men of letters gave rise to（引起,导致,产生）yet another school of realism: American .A. modernismB. naturalismC. vernacularismD. local colorismAnswers: A B12. While embracing the socialism of Marx, London also believed in the triumph of the strongest individuals. This contradiction is most vividly projected in the patently（明白地;公然地）autobiographical novel .A. The Call of the WideB. The Sea WolfC. Martin EdenD. The Iron Heel13. The main theme of The Art of Fiction reveals his literary credo（信经,信条）that representation of life should be the main object of the novel.A. Henry James'B. William Dean Howells'C. Mark Twain…sD. Jack LondonAnswers: C A•1. The Age of Realism is also what Mark Twain referred to as . •The Gilded Age•2. In 1859, Darwin published , which exerted great influence on American Naturalism.•Origin of the Species•3. is regarded as "the true father of our national literature." •Mark Twain•4. The name of the heroine in The Portrait of a Lady is .•Isabel Archer•5. The Financier, The Titan and The Stoic form Dreiser's . •Trilogy of Desire•6. An American Tragedy is a masterpiece by . •Theodore Dreiser。
生物工程专业英语翻译
Beijing University of Chemical Technology 化学工业出版社• Exercise for Chapter 1Line 1-10, P. 1生物工程是属于应用生物科学和技术的一个领域，它包含生物或其亚细胞组分在制造业、服务业和环境管理等方面的应用。
生物工程利用细菌，酵母，真菌，植物细胞或培养的哺乳动物细胞作为工业加工的组分。
只有将微生物学、生物化学、遗传学、分子生物学、化学和化学工程等多种学科和技术结合起来，生物工程的应用才能获得成功。
Biotechnology is an area of applied bioscience and technology which involves the practical application of biological organisms,or their subcellular components to manufacturing and service industries and to environmental management.Biotechnology utilizes bacteria,yeasts，fungi，algae，plant cells or cultured mammalian cells as constituents of industrial processes.Successful application of biotechnology will result only from the integration of a multiplicity of scientific disciplines and technologies,including microbiology,biochemistry,genetics,molecular biology,chemistry and chemical and process engineering.line3 ---line7, P.6生物科学和生物工程之间有一个很明显的区别。
国家开放大学电大《高级英语阅读(1)》《纳税筹划》网络课形考网考作业(合集)答案
国家开放大学电大《高级英语阅读(1)》《纳税筹划》网络课形考网考作业(合集)答案《高级英语阅读(1)》网络课答案形考任务一（70分）Chapter 1 Exercise（分值7分）题目1I. Vocabulary skills（3 points）Look at the columns below. Match each vocabulary word on the right with the correct definition on the left.(0.5 points each)1.the bus or subway2.proof of completion of courses of students3.money for students from scholarships, grants, or loans4.formal talks by professors or instructors on subjects of study5.courses by video, video conferencing, or computers to students in different places6.the points or grade a student gets on a test答案：II. Reading Comprehension (4 points)Read the passages, then answer the questions that follow. (1 point each )Experiencing Culture ShockA When Eliza James arrived at the University of Xian, she was excited to live in a new country, to improve her Chinese, and to experience a culture so different from her own. But soon her excitement turned to frustration as she encountered one roadblock after another. "I felt like I couldn't accomplish anything. My dorm room had no heat, I couldn't get into the classes I wanted, and every time I asked someone for help they gave me the runaround. I felt like no one was listening to me." Eliza met with administrators, sentletters of complaint, and even contacted the consulate in Beijing, but she got nowhere. What Eliza didn't realize was that her American approach to solving problems was very different from the Chinese one in which patience and negotiation skills are key. She soon learned how to solve problems within the cultural norms of Chinese society instead of forcing her own values onto those around her. "I finally feel like I fit in and that I know what I'm doing. In fact, it's really fun being in a place that's so incredibly different from what I am accustomed to."B Yoshi Yamamoto is a junior at a small college outside of Boston. Although he is an honors student now, Yoshi didn't always have such an easy time studying in America. "Teaching methods are very different here than they are in Japan. It took me a long time to get used to learning in seminars and discussing ideas with my classmates. At first it seemed like I wasn't actually learning anything." Yoshi's reaction was to totally withdraw: he didn't participate in class discussion; he spent lots of time alone in his room, and he even skipped class on occasion. "I thought I could teach myself. Now I recognize the value of the U.S. academic system, and I am able to adapt it to my own learning style."C Both Eliza and Yoshi experienced what is called culture shock: psychological disorientation due to living in a new culture. For many international students, studying abroad can offer exposure to new cultures and an opportunity to study new fields and languages. However, it also offers the greater challenge of trying to function in a foreign culture. Studying and reading about a certain culture is poor preparation for the reality of living in it. According to psychological studies, the four stages of culture shock are 1. euphoria, 2. hostility, 3. gradual adjustment, and 4. adaptation. Culture shock can be manifested in many ways: homesickness, boredom, stereotyping of or hostility towards the host culture, overeating or overdrinking, withdrawal, and inability to work effectively.D Different people experience different levels of culture shock and react in different ways. For example, Eliza got angry while Yoshi withdrew from society. The most important thing to remember is that culture shock is normal; it is not something to be ashamed of. Luckily, there are some things international students can do to make their adjustment to a new country go more smoothly. For instance, they can stay in touch with family and friends from home, join international student organizations, meet people from their own countries, and get involved in campus activities. Most importantly, they can adjust to life abroad by keeping a sense of humor and trying to remain positive.Recognizing Paragraph Topics（choose the paragraph letter）题目27. an explanation of culture shock选择一项：A. AB. BC. CD. D题目38. ways that students can adjust to living in a new country选择一项：A. AB. BC. CD. D题目49. the experience of an international student in the United States选择一项：A. AB. BC. CD. D题目510. the experience of an international student in China选择一项：A. AB. BC. CD. DChapter 2 Exercise（分值7分）题目1I. Vocabulary Skills（2 points）Sometimes examples can explain the meaning of a word or phrase. For example, sun, rain, and wind are examples of kinds of weather. Look at the columns below. Match each vocabulary word or phrase in the first column with the examples in the second column. (0.4 points each)1.kinds of extreme weather2.Earth’s natural materials and gases3. diseases or health disorders4. seasons of the year5. natural areas or regions of the earth答案：II. Reading Comprehension (5 points)Complete the following statements by choosing the best from the answers A, B or C. (1 point each) Seasonal Affective Disorder: More than Just the BluesA Joshua dreads the winter months, not only because of the cold New England weather--the sleet, snow, wind, and rain--but because as the seasons change from summer to fall to winter, the days get shorter. As the days get shorter, he starts feeling depressed and irritable and spends more and more time at home, eating and sleeping. A graduate student in philosophy, Joshua finds that he gets little work done during the winter months and has trouble paying attention in class and concentrating on his research. "I soon realized that what I thought was just the 'winter blues' was something more extreme than that." Josh visited a doctor who diagnosed him with SAD.B Seasonal Affective Disorder, or SAD, is a kind of depression that occurs seasonally. It is associated with the long hours of darkness and lack of sunlight during the winter months (people with SAD usually feel worse from December through February). Scientists don't completely understand the exact causes of SAD, but they believe it is related to a biochemical imbalance in the hypothalamus. The hypothalamus is the basic part of the brain that controls the body's breathing, heartbeat, metabolism, and hormone release. The effects of SAD include moodiness, irritability, low energy, increased appetite for carbohydrates (foods such as potatoes, rice, and bread), difficulty concentrating, and the tendency to oversleep.C Although doctors described SAD for the first time in 1984, humans have probably dealt with the disorder for thousands of years. It is not a coincidence that many cultures have important celebrations during the short days of the winter months. Christmas, Hanukkah, and Winter Solstice celebrations all occur in December. These celebrations involve lighting candles in order to bring light, warmth, and happiness to an otherwise depressing time of year.D So what can SAD sufferers do to feel better? Naturally, they need more light. For people who have mild cases of SAD, exercising in the morning sun could be enough to help them. Phototherapy, or light therapy, is usually prescribed for people who have more serious cases of the disorder. In light therapy, patientssit in front of a light box, a strong artificial light, for up to four hours a day. Phototherapy is effective in over 80% of SAD cases, and patients usually see results within three to four days. Although the symptoms of SAD are similar to those of clinical depression, traditional antidepressants have not proven useful in treating SAD. While psychological counseling cannot treat the symptoms of SAD, it is recommended to help SAD sufferers learn to accept and deal with their illness.题目26. Joshua starts feeling depressed and irritable in the winter because选择一项：A. he gets little work doneB. he suffers from Seasonal Affective DisorderC. he is a graduate student in philosophy题目37. Seasonal Affective Disorder, or SAD, is a condition that researchers believe affects people during the winter months. Scientists believe it is caused by选择一项：A. breathing, heartbeat, metabolism, and hormone releaseB. moodiness, irritability, loss of energy, increased appetite, difficulty concentrating, and sleepinessC. lack of sunlight and a biochemical imbalance in the brain题目48. Humans have probably struggled with SAD since选择一项：A. ancient timesB. DecemberC. 1984题目59. People who suffer from SAD can to feel better.选择一项：A. do light therapyB. take antidepressant drugsC. eat carbohydrates题目610. This passage talks about_____.选择一项：A. what the SAD effects areB. Both A and B.C. how to help SAD suffersChapter 3 Exercise（分值7分）I. Reading Comprehension (5 points)Read the passages, then answer the questions that follow. (1 point each )Fast food can be good foodMany people are too busy to prepare and eat three nutritious meals a day.so they turn to the convenience of fast-food restaurants. Many of the items at fast-food restaurants, snack bars, and food stands are fattening and not very nutritious.But fast food doesn’t have to be unhealthy.you can eat at fast-food restaurants and still eat well.Pay Attention to Calories and Fat ContentBy paying attention to the number of calories and fat that a food item has ,you can make smarter choices.Calories are “units for measuring how much energy a food will produce”.condsider two fast-food meals. A quarter-pound hamburger with cheese, jumbo-size fries,and a 16-ounce soda have a total of 1,535 calories and 76 grams of fat .a broiled (cooked under direct heat or over a flame )chicken sandwich ,a side salad with low-fat dressing,and a glass of water at the same fast-food restaurant have only 422 calories and 7 grams of fat .but maybe you really want a hamburger and fries .well,you can have a small hamburger,a small serving of fries,and a glass of water.At a total of 490 calories and 20 grams of fat,that’s still a much smarter choice than the large burger ,fries,and 20 grams of fat ,that’s still a much smarter choice than the large burger,fries,and sada.There’s More That You Can DoThere are a few additional things you can do to make sure you eat well in fast food restaurantS.First of all,say “no” when the cashier asks you if you want to “supersize” you meal (order an extra large portion of each item).Second, ask for no mayonnaise or sauce,or ask for it on the side (in a separate dish).Third,substitute(use something instead of something else)healthy foods for fatty ones. For example,instead of ordering deep-fried tempura,order fresh vegetables.Instead of ordering a beef burrito with lots of cheese and sour cream,order a vegetable burrito with beans and rice.and don’t eat the chips!Another thing you can do is order a side salad or a vegetable soup and eat it first.That way,you will eat some vegetables,and you won’t be able to eat as much of your burger and fries.Fnally,eat slowly and stop eating when you’re full. It sounds simple,but many people keep eating even after they become full.题目11.What is the main idea of this article ?________选择一项：A. It’s smart to eat foods with low calories and fat content.B. Fast food is always bad for you .C. You can eat well in fast-food restaurantD. Fast-food restaurants are the best the place to find healthy foods . 题目22.A small hamburger and small firies has __________选择一项：A. more calories and fat than a chicken sandwich and a salad.B. the same amount of calories and fat as a chicken sandwich and a salad.C. fewer calories and fat than a chicken sandwich and a salad.D. the same amount of calories and fat as a large portion of fries.题目33.Some things you can do to eat well in fast-food restaurants are________ 选择一项：A. ask for eatra manyonnaise and sauce and say no to “surpersizing” .B. order a vegetable burrito instead of chips and eat sour cream .C. order smaller portions and eat all the food you order.D. order healthy foods instead of fatty ones and drink water.题目44.Manyonnaise and sauces probably_________选择一项：A. make you eat less because they make you feel full sooner.B. make you eat more because they make your food taste better.C. have a lot of fat and calories.D. don’t have a lot of fat and calories.题目55. By eating a salad or soup before the rest of your meal,_______选择一项：A. you eat less of the rest of your meal.B. you eat more slowly.C. you get full sooner.D. you eat the rest of your meal more quickly.II. Vocabulary skills（2 points）Read the paragraph below and fill in each blank with a word from the box. (0.4 points each)题目6changes damaging losing global availableThe growing similarities in diet and eating habits around the world are influencing people of various cultures in different ways. For example, Western foods are 6 damaging health in the industrialized island country of Japan. Instead of small meals of seafood, rice, and vegetables, the typical Japanese diet now includes large amounts of meat, dairy products, and desserts like tiramisu, a rich Italian dish full of chocolate, cheese, and sugar. According to Japanese health researchers, such 7 changes in eating habits are related to a great increase in health problems such as heart disease, strokes, cancer, and diabetes. On the other hand, the changing 8 global diet is having the opposite effect on the people in the CzechRepublic. The government of this European nation no longer supports meat and dairy products financially, so the cost of these foods is going up. In contrast, fresh fruits and vegetables are becoming more widely 9 available from private markets and stands. Cooks are even serving salads to schoolchildren, and families are eating healthier home-cooked meals. For these reasons, fewer Czech men are having heart attacks, the women are 10 losing a lot of weight, and most people are living healthier lives.Chapter 4 Exercise（分值7分I. Vocabulary Skills（2 points）题目1Match each vocabulary word on the left with the correct definition on the right. (0.4 points each)1.make sense2.pedestrians3.vehicle4.teenager5.fine答案：II. Reading Comprehension (5 points)Complete the following statements by choosing the best from the answers A, B, C, or D. (1 point each) These days, it’s getting easier and easier to find your way around. Some people have GPS devices in their cars to make sure they don’t get lost. GPS stand s for Global Positioning System. These devices use satellites in space to “see” where you are and give you directions to where you want to go. And if you don’t have a GPS device, you can simply go online to get step-by-step directions. Websites like and can produce a map and directions in just a few seconds. But how do they do it? MapQuest® uses data (information) from a few different sources to produce directions and maps. Before MapQuest® went online, it sold regular paper ma ps in places like gas stations. The website uses the data from those paper maps, information from digital mapping companies, and government databases. At the moment, MapQuest® uses more than 30 computers to read all this data and provides users with millio ns of maps every day.In order to find the best route (way or path) from one place to another, MapQuest® first has to look at all possible routes. Then MapQuest® looks at each part of each possible route. It considers the types of roads on the different routes. Are they dirt roads, paved roads, freeways, or city streets? It looks at how many turns there are in each route and what kinds of turns they are. Are they right turns or left turns? It also considers the speed limit on each road and how many intersections there are. An intersection is “a place where two or more roads cross each other”.MapQuest® can also tell you how long your trip will take you. It does this by doing some math. MapQuest® bases its estimated driving times on the length and speed limit of each part of the route and the amount of time it probably takes to get through each intersection. For example, it allows more time for a left turn at an intersection than it does for a right turn. Someday, maybe we will have cars that can just drive us wherever we want to go, but for now, mapping websites make it a little harder to get lost.题目26.What is the main idea of this article?选择一项：A. Why mapping websites don’t work well.B. Why mapping websites are better than paper maps.C. How mapping websites work.D. How the first mapping website started.题目37.According to the article, MapQuest®______选择一项：A. started as maker of government databases.B. started as an Internet company.C. uses millions of computers to read data.D. starting by selling paper maps.题目48.When you search for directions, the first thing MapQuest® does is_______选择一项：A. consider how many turns you want to take.B. print out a map and directions.C. estimate driving time.D. look at all possible paths.题目59.When it’s deciding on the best route, MapQuest® probably chooses ________选择一项：A. the route with the most turns.B. dirt roads instead of paved roads.C. freeways instead of dirt roads.D. city streets instead of freeways.题目610. To estimate your driving time, MapQuest® considers _________选择一项：A. the distance between turns on your route.B. the speed limit for half of the route.C. the fastest and slowest speed limits on your route.D. the speed limits and types of turns on your route.Chapter 5 Exercise（分值7分）I. Reading Comprehension (5 points)Read the five main-idea questions that follow about the information in the reading. Three details correctly answer each question. Cross out the untrue, unrelated detail. (1 point each )题目11. What are the definitions of the two main types of families?选择一项：A. Human beings lived in loosely-related groups. Each group had a common ancestor long time ago.B. The nuclear family consists of two parents and their biological or adopted children.C. The extended family may include grandparents, parents, children and relatives living together on the same street or in the same area.D. The nuclear family is the same as the extended family.题目22. What are the reasons for the changes in the structure of the family?选择一项：A. The divorce rate went down and the birthrate began to rise in the early 1900s in the United States.B. Couples did not want many children then.C. In the early 1900s in the United States, the divorce rated went down and the birthrate went down.D. At that time, couples were staying married for few years.题目33. What happened to families in industrialized countries in the 1930s and 1940s?选择一项：A. Before and during World War II, families faced few financial problems and women didn’t have to work away from home.B. Men were at war, so women had to work outside the home.C. Before and during World War II, families had problems.D. Families had serious financial problems during World War II.题目44. What changes will happen to family structure during the next decades?选择一项：A. Divorces would be fewer, mothers would stay at home after the war.B. Children began living at home longer.C. After the war, family structure changed back.D. After the war, there were more divorces and fewer stay-home-mothers.题目55. What will families be like in the future?选择一项：A. Many people want the traditional two-parent family back.B. Two-parent family will probably come back and all other family forms will end.C. Unmarried parents with adopted or foster children, and one-person households.D. There may be more single-parent families.II. Vocabulary Skills（2 points）Read the paragraph below and fill in each blank with a word from the box. ( 0.4 points each)题目6living extended category typical believeThe Family of the FutureMany people today would like the traditional two-parent family back—that is to say, they want a man and a woman to marry for life; they also think the man should sport the family and the woman should stay home with the children. However, few families now fall into this 6 category In fact, if more women decide to have children on their own, the single-parent household may become more 7typica l than the traditional family in many countries. Also, unmarried couples may decided to have more children—or they might take in foster children or adopt. And because people are staying single and 8 living longer (often as widows), there may be more one-person households in the future. On the other hand, some people 9believe similar events happen again and again in history. If this is true, people may go back to the traditional 10 extended or nuclear family of the past. Others think the only certainty in history is changing: in other words, the structure of the future family could begin to change faster and faster—and in more and more ways.Chapter 6 Exercise（分值7分）I. Vocabulary skills（2 points）Complete the following statements by choosing the best from the answers A, B, C, or D. （0.4 points each）题目11. Some examples of the architecture of old Europe are the magnificent cathedrals and castles. The design and building styles of modern architecture are excellent too. What does the noun architecture mean in these sentences?选择一项：A. the place with significant civilization everywhereB. people that study the culture of old Europe and other societiesC. the art and science of designing the study of classical literatureD. the form and plan of buildings and other structures题目22. Perhaps the real beginning of civilization—with its scientific and technological discoveries and inventions—was in the Middle East and Africa. Over five thousand years ago, those ancient civilizations had astronomy, mathematics, medicine, government, and so on. Which word is a synonym of the word civilization? 选择一项：A. technologyB. cathedralC. cultureD. astronomy题目33. The cultural legacy of ancient Chinese and Indian peoples included walled cities, the first governments, tools for work, and weapons for protection. odern peoples built on this legacy.What is a possible explanation of the word legacy?选择一项：A. ideas and achievements passed from earlier generations to modern societyB. a gift of money that somebody gives to another personC. international business conducted in cities and government structuresD. the state or condition of being legal; not against the law题目44. “For me, the idea of ancient culture creates a contradiction in definitions,” said Karen, going against Mei’s views. “Only modern things can be part of culture.Of course, people that like classical art and music will contradict me.”What might the noun contradiction mean?选择一项：A. the opposition of two opinionsB. wearing a Hawaiian shirt in an ancient cultureC. the short forms of two words togetherD. to put words together题目55. Because of the worldwide media—movies, TV, CDs, the Internet, newspapers, magazines—everybody knows the same information, plays the same music, and enjoys the same jokes.How might you define the phrase the media?选择一项：A. the combination of visual, sound, and printed ways to send ideas around the worldB. communication styles include motions, gestures and facial expressionsC. the tradition of being in the middle—not on the extremes of possible viewsD. events that appear in the daily news and that everyone knows aboutII.Reading Comprehension (5 points)Decide whether the following statements are true or false. Write “T” for True and “F” for False. （1 point each）Many visitors to different countries don’t realize how important it is to understand a country’s culture. Sometimes people learn this lesson by making a big cross-cultural blunder, or embarrassing mistake. In business situations, these blunders can cost a lot of money or end business relationships.6.It is important to understand other people’s cultures before you do business with them.选择一项：A. FB. T题目7For example, one company wanted to sell toothpaste in Southeast Asia. In their advertisements, they claimed that their toothpaste whitens teeth. They didn’t understand that many of the local people chewed betel nuts to make their teeth black, and that these people thought black teeth were attractive.7. The toothpaste company probably kept using the same advertisement in Southeast Asia.选择一项：A. FB. T题目8In another case, a car company tried to sell a car called “Matador” in a Spanish-speaking country. The company thought that it was a strong name because it means “bullfighter”. In Spanish, matador is indeed a noun meaning “bullfighter”. But it is also an adjective meaning “killing”. Imagine driving around in a car called “Killing”!8. The car company that tried to sell a car to a Spanish-speaking country probably didn’t sell many Matador cars in that country.选择一项：A. FB. T题目9A European businessman had an important meeting with a company in Taiwan. He wanted to bring gifts for the people he was meeting with. He thought that something with his company’s logo on it would be a nice gift. So he bought some very nice pocket knives and h ad his company’s logo printed on them. He didn’t know that giving a knife as a gift symbolizes cutting off a friendship!9. The European businessman probably researches new cultures before he visits them now.选择一项：B. F题目10It’s very easy to make blunders like these people did. But it’s also very easy not to. Before you visit a new country, research that country’s customs and etiquette (social rules for polite behavior). You can find a lot of information online. Just go to a search engine and type in key words like “cross-cultural etiquette” or “cultural information Taiwan”. By spending a few minutes doing research, you can save yourself from a lot of embarrassment and make sure you don’t accidentally off end anyone.10. What you can disagree with people to save yourself from making cross-cultural blunders.选择一项：A. TB. FChapter 7 Exercise（分值7分）I. Reading Comprehension (5 points)Decide whether the following statements are true or false. Write “T” for True and “F” for False on the Answer Sheet. (1 point each)题目1For instance, a doctor doesn’t always have time to thoroughly explain an illness. In these cases, the Internet can be a valuable resource—a place to read all about the causes, symptoms, and remedies for an illness.1. One benefit of using the Internet as a medical resource is it has a lot of information about illnesses and diseases.选择一项：A. FB. T题目2For example, some websites claim that sniffing (smelling) a newspaper can cure nausea (the feeling of being sick to your stomach and wanting to vomit).2. One possible remedy for nausea is drinking a lot of tea.选择一项：A. TB. F题目3Other websites suggest that a person with a cold should keep a piece of raw garlic in his or her mouth allday and bite down on it every few minutes to release the juice. People with smelly feet are told to soak their feet in tea for half an hour.3. The websites remedies might be unpleasant or odd, but they probably will cause harm. And who knows? They might actually be unhelpful.选择一项：A. FB. T题目4An herbal remedy for helping your memory may also be a blood thinner. So if your doctor prescribed (put you on) a blood thinner and you start taking this herb without asking your doctor about it, a simple cut could be deadly; you might not be able to stop bleeding.4. A person who is taking a prescribed drug should probably talk to the doctor before taking an herbal remedy.选择一项：A. FB. T题目5The bottom line is this: be careful when using the Internet as a health resource. Use it to find information that you can discuss with your doctor. But don’t spend a lot of money on “miracle cures”.5. The best way to use the Internet as a medical resource is to read about your illness and discuss what you find out with your doctor.选择一项：A. TB. FII. Vocabulary skills（2 points）Read the paragraph below and fill in each blank with a word from the box. ( 0.4 points each)题目6disease substance classification prevent figureIn a small-town farm market, hundreds of elderly people drink a glass of sour dark cherry juice every day. These happy senior citizens, some of them over the age of 90, claim that the natural fruit juice cures—or at least decreases—the pain of their arthritis, a 6 disease of the joints of the aging body. It’s a folk remedy, not a proven medical therapy. Nevertheless, science is beginning to 7 figure out why sour cherry juice might work to improve the health of patients with arthritis. The secret is in the 8 substance that。
Supplementary Exercises for English Lexicology (Chapter 2)
Chapter 2: The Development of the English Vocabulary▪Choose the best answer that would complete the statement among the four alternatives.1.The Indo-European language family accordingly fall into ____ principle groups,which can be grouped into an Eastern set and Western set.A. eightB. sixC. fiveD. several2.In the Eastern set, ____ and ____ are each the only modern language respectively.A. Italic, GermanicB. Albanian, ArmenianC. Celtic, HellenicD. Balto-Slavic, Indo-Iranian3.All these languages have some influence on English to a greater or lesser extentbecause each has ____ the English vocabulary.A. borrowed words fromB. enlarged words toC. decreased words toD. lent words into4.Indo-Iranian comprises the modern languages except ____ .A. PersianB. BengaliC. Hindi, RomanyD. Polish5.In the growth of present-day English vocabulary, there are three main sources ofnew words, the rapid development of modern science and technology, social, economic and political changes and the influence of ____ .A. the educational systemB. other cultures and languagesC. the government systemD. the society changes6.The most important way of vocabulary development in present-day English is____ .A. borrowingB. semantic changeC. creation of new wordsD. all the above7.Old English vocabulary was essentially with a number of borrowings from Latinand Scandinavian.A. ItalicB. GermanicC. CelticD. Hellenic8.Old English has a vocabulary of about ____ words.A. 30,000 to 40,000B. 50,000 to 60,000C. 70,000 to 80,000D. 80,000 to 90,0009.Besides French words, English also absorbed as many as 2,5000 words of ____ inthe Middle English period.A. Dutch originB. Danish originC. Latin originD. Greek origin▪Complete the following statements with proper expressions according to the textbook.1.The language used between 450 and 1150 is called ____ English.2.Words of old English were full of ____ .3.Old English has a vocabulary of about ____ to ____ words.4.Old English was a highly ____ language just like modern German.5.The first peoples known to inhabit the British Isles were ____. Their languageswere ____ .6.Old English was influenced by Latin, ____ and Danish.7.By the end of the ____ century, English gradually came back into the schools, thelaw courts, and government and regained social status.8.Between 1250 and 1500 about ____ words of French origin poured into English.____ percent of them are still in sue today.9.Modern English vocabulary grow through three major channels: ____ , semanticchange and ____ .10.____ refers to the formation of new words by using roots, affixes and otherelements.11.____ means an old form which taken on a new meaning to meet the new need.12.____ is the most important way of vocabulary expansion on modern times.13.Reviving archaic or ____ words also contributes to the growth of Englishvocabulary though quite insignificant.14.The language used in the English between 450 and 1150 is ____ .▪Decide whether the following statements are true or false.1.Modern English began with the Renaissance.2.Considering the changes in vocabulary, modern English can be divided into twostates.3.During the Renaissance, enormous numbers of Latin words became part ofEnglish vocabulary.4.Modern English is a synthetic language.5.Borrowing remained the most important channel of vocabulary expansion in latemodern English.▪Define the following terms.1.Old English:▪Question and answer.1.Why do we say “English is a heavy borrower”? Please justify it.。
抽象代数Chapter2习题答案
HW 2 Solutions, (October 5th, 2011)
All problems from Chapter 2 of Artin’s Algebra. 1.3 If map r : N → N was a right inverse for the shift map s, then the composition sr would send 1 to 1. However, the number 1 is not in the image of s so such a right inverse is impossible. For any n ∈ N, define the map ℓn by ℓn (i) = i − 1 if i ≥ 2 and ℓn (1) = n. Then the composition ℓn s is the identity on N. Thus we have exhibited an infinite number of left inverses. 2.1 Group multiplication table for S3 = {e, (12), (13), (23), (123), (132)} with first row (resp. column) corree (12) (23) (13) (123) (132) (12) e (123) (132) (23) (13) (23) (132) e (123) (13) (12) sponding to left (resp. right-) multiplication by identity e: . (13) (123) (132) e (12) (23) (123) (13) (12) (23) (132) e (132) (23) (13) (12) e (123) 2.2 Let S ′ be the subset of S consisting of invertible elements. We must show that the associative law of composition, ◦, on S restricts to a law of composition on S ′ . In other words, we need to show closure: if s1 and s2 are invertible (i.e. in S ′ ), then s1 ◦ s2 is also invertible (i.e. in S ′ ). But this is clearly true since 1 −1 ′ s− 2 ◦ s1 is the inverse of s1 ◦ s2 . This law of composition on S is associative since it is associative on S . To complete the proof that subset S ′ is a group, we need to check that identity and inverses are in S ′ , and these follow quickly. 2.4 a) Yes, GLn (R) is a subgroup of GLn (C), clearly the product of two invertible matrices with real entries is an invertible matrix with real entries (implies closure ). The identity matrix has real entries, and the inverse of a matrix with real entries also has real entries. b) Yes, {−1, 1} is a subgroup of R× . (Similar technique as in part (a).) c) No, the inverse of a positive integer (under addition) is not a positive integer. d) Yes, {positive reals} is a subgroup of R× . (Similar technique as in part (a).) e) No, matrix a 0 is not invertible. 0 0 1
英语专四练习sublist 2 exercise with keys
Sublist 2achieve acquisition administration affect appropriate aspects assistance categories chapter commission community complex computer conclusion conduct consequences construction consumer credit culturaldesign distinction elements equation evaluation features final focus impact injuryinstitute investment items journal maintenance normal obtained participation perceived positive potential previous primary purchase rangeregion regulations relevant resident resources restricted security sought select sitestrategies survey text traditional transferExercise 1assist evaluate credit primary compute resident achieve institute obtain site1. He _______________ a final mark of just over 80%. obtained2. If I can _______________ you in any way, please let me know. assist3. We have to give her a lot of _______________ for our success. credit4. The government is looking for a _______________ on which to build a new school in this area. site5. The _______________ reason he has done so well at school is that he works incredibly hard. primary6. Firemen had to evacuate the elderly _______________ of a local nursing home after smoke was seen coming from one of the rooms. residents7. If you want to _______________ real progress in your speaking skills, you need to speak English as often as possible while you are here. achieve8. The English Program has _______________ many changes over the years in an attempt to provide an increasingly better program. instituted9. The results of the poll have now been _______________, and will be distributed to the news media this afternoon. computed10. Every employee's work performance will be _______________ on a yearly basis. evaluated11. Mikhail Gorbachev is _______________ with helping to bring about the end of communism in Europe. credited12. She _______________ the doctor during the operation. assisted13. _______________ valid results is a major goal of all research. achieving14. World chess champion Gary Kasparov was recently beaten by a machine which was able to _______________ its moves almost instantly. compute15. Teachers in the program are _______________ by the students at the end of each session. evaluated16. Fire crews rushed to the _______________ of the plane crash. site17. Vitamins are best _______________ through fresh fruit and vegetables, rather than by takingpills. obtained18. Calcium is the _______________ mineral needed for building and maintaining strong bones. primary19. Local _______________ are delighted with the new water park for children. residents20. The government has _______________ a couple of changes to the driver's licensing procedure in an attempt to reduce the number of accidents involving new drivers. instituted Exercise 2feature resources category participate invest conclude acquire purchase strategy culture1. She won awards in both the best female vocalist, and best album of the year _______________. categories2. In the _______________ of Japan, people bow to each other when they meet. culture3. Steven Spielberg announced the release of his newest film, _______________ Tom Cruise, at the film festival. featuring4. Did you _______________ anything of value while you were travelling in the U.S.? purchase5. Before _______________ in a new dictionary, look up a couple of words in a few different ones so you can see which one has the clearest definitions. investing6. In this course we will be teaching you a number of different _______________ which will help you learn to read more quickly in English. strategies7. ESL students in this program are encouraged to _______________ in as many activities as possible in order to get to know people, and practise speaking English. participate8. Karla had _______________ a bit of an English accent after living in London for 5 years. acquired9. If you are giving a speech, remember that if you _______________ five minutes early, your audience will be quite happy, but if you _______________ five minutes late, they may be angry or impatient. conclude10. Canada is a country which is rich in natural _______________ such as lumber, fish, and clean water. resources11. Malaysia's natural resources fall into three basic _______________: agricultural, mineral, and energy. categories12. Parrots, most famous of all talking birds, rarely _______________ a vocabulary of more than twenty words. acquire13. The bacteria _______________ that we examined under the microscope was actually quite beautiful to look at. culture14. This company needs to _______________ in new machinery if it wants to survive. invest15. Paul Nation has noted that the most successful second language students are those who use several different vocabulary learning _______________. strategies16. The landscape of our planet is dominated by _______________ formed by running water. features17. The American Psychological Association has _______________ that viewing violence on TV promotes aggressive behaviour in children. concluded18. Our company simply doesn't have the _______________ to take on a project of that size. resources19. Everyone who _______________ in the run will receive a free T-shirt. participates20. It is said that the island of Manhattan was _______________ from the native people of the area for about $24 worth of goods. purchasedExercise 3restrict perceive chapter conduct surveydesign range administer final item1. She is currently working on _______________ a new publicity campaign for the local department store. designing2. The government is _______________ tests of a drug that may prove useful in the fight against AIDS. conducting3. I read the first _______________ of the book last night, and it seems pretty good. chapter4. During the experiment, the drug was _______________ to a monkey, and the results were studied. administered5. You should make up a list of the _______________ you want to take with you on your trip. items6. There is a wide _______________ of abilities in our tennis club, from absolute beginners to those who have played professionally. range7. Traffic in these lanes is _______________ to vehicles with 3 or more passengers. restricted8. Children do not always _______________ the relationship between success and effort in the things they do. perceive9. A recent telephone _______________ of over 1,000 households revealed that over 70% of Canadian families now recycle. survey10. All the students were dressed up for the _______________ banquet. final11. We need to make up an _______________ list of everything required before beginning work on building the playground. itemized12. His divorce marked the beginning of a new _______________ in his life. chapter13. Although we cannot count every star in our galaxy, we can take a _______________ in the region of space near our sun. survey14. She was wearing a beautiful black dress with a _______________ of red roses down the side. design15. A large fence _______________ access to the area. restricts16. In response to Indian nuclear weapons testing, Pakistan _______________ its own tests in 1998. conducted17. The Cayman Islands have been _______________ by Jamaica since 1863. administered18. We _______________ the contract this afternoon. finalized19. Summertime temperatures in this region _______________ between 20 and 30 degrees. range20. Cigarette smoking is widely _______________ as being the most serious health issue in society today. perceivedExercise 4positive affected focus region commission distinct journal consequence secure text1. He broke the law, and now he has to face the _______________ of his actions. consequences2. The local government has _______________ a study to see if it is worth trying to save some of the old historic buildings downtown. commissioned3. Japan covers four _______________ climate zones, from the tropics of Okinawa to the snow country of the far north. distinct4. The results of the experiment were published in an important chemistry _______________. journal5. Her brother has just tested _______________ for AIDS, so she is very upset. positive6. You are trying to do too many things at once. It would be better to just _______________ on one thing in order to do it properly. focus7. The professor's lecture just repeated what is written in our assigned _______________. text8. His job doesn't pay very well, but it is very _______________, so he doesn't really want to give it up. secure9. The economy of Canada has been _______________ a great deal by the Asian economic crisis. affected10. In some _______________ of Canada, winter lasts more than half the year. regions11. Make sure you _______________ the boat with a good rope or it will float away. secure12. On November 3rd, 1507, the great Leonardo DaVinci was _______________ to paint the portrait that is known today as the Mona Lisa. commissioned13. We went on a wonderful tour of the wine-producing _______________ of British Columbia last summer. regions14. His outlook on life became much more _______________ once he found a job, and began getting a regular salary. positive15. The centre of the planet Earth is believed to consist of two _______________ parts, with a liquid outer core surrounding a solid inner core. distinct16. The children were greatly _______________ by the divorce of their parents. affected17. If mankind fails to address the problem of pollution, future generations will face the terrible _______________ of our inaction. consequences18. Sue is planning to study _______________, and hopes to become a television news reporter. journalism19. My photos didn't turn out very well. I think my hand must have been shaking a little bit because they're all out of _______________. focus20. The Internet can be used to access huge amounts of information in the form of _______________, graphics, sound, and video. textExercise 5construct impact potential maintain tradition appropriate seek element regulate community1. Changes in the American economy generally have a serious _______________ on our economy here in Canada. impact2. Most immigrants to Canada try to preserve the culture and _______________ of their home country for their children. traditions3. Water and salt both work to _______________ the water content of the body. regulate4. People in this _______________ want to keep the area safe for children to play in. community5. I don't really think that it is _______________ to wear jeans to the office. appropriate6. The Great Wall of China was _______________ to keep out enemy invaders. constructed7. There are 109 different _______________ in the Periodic Table in chemistry. elements8. Tian Hsu works hard to _______________ close friendships with the students she studied with in London. maintain9. My great-grandfather came to Boston to _______________ his fortune in the early 1800s. seek10. Scientists are only beginning to recognize the _______________ benefits of using ocean tides as a source of endless, clean energy. potential11. Some of the vocabulary which we are studying is slang, and is not _______________ in certain situations. appropriate12. The black _______________ is protesting the treatment of black youths arrested by police in recent months. community13. Aristotle believed that the universe is composed of 4 _______________: earth, air, fire and water. elements14. Women in Japan usually wear a _______________ wedding kimono for at least part of their marriage ceremony. traditional15. Some people think that access to the Internet should be _______________ so that children are not exposed to pornography. regulated16. All the extra-terrestrials were killed by the _______________ when their spaceship slammed into the Eiffel Tower. impact17. Bill Gates has _______________ the largest computer empire in the world. constructed18. Buddhism teaches that the _______________ to become a Buddha is already contained within us. potential19. Two masked men are being _______________ by police for robbing a number of convenience stores. sought20. The city can no longer afford to _______________ the zoo, and will sell all the animals that are remaining. maintainExercise 6aspect injure normal transfer complex relevant previous equate select consume1. Our new washing machine _______________ about half the electricity of our old model.consumes2. The issue is much too _______________ for me to understand. complex3. We need to really look at all the _______________ of this deal before we decide whetheror not to accept it. aspects4. In a _______________ week, you can expect to study between 15-20 items of vocabularyin this class. normal5. She _______________ her back lifting a heavy box while she was moving into her new apartment. injured6. Our _______________ house was much smaller than this new one. previous7. She has just been _______________ as a member of Canada's Olympic volleyball team. selected8. Talking about the personal life of employees is not _______________ to a discussion of their ability to do their job. relevant9. We moved from Halifax to Vancouver when my father's company _______________ him to their main office out here. transferred10. Many people _______________ Canada with snow, but in the city where I live, sometimes we don't get any snow all winter. equate11. Patricia Chan has been _______________ to represent this company at the New York conference. selected12. Politics are too _______________ for me to understand, and I don't even know who to vote for. complex13. Teaching students to have realistic expectations is an important _______________ of second language instruction. aspect14. An adult grey whale _______________ about 1,100 kilograms of food per day. consumes15. Please ensure that you attach all the _______________ documents to your application. relevant16. The African continent is often _______________ with images of starving children, but many of the people there live quite comfortably. equated17. The original inhabitants of New Zealand, the Maori, _______________ their history down the generations largely by word of mouth. transferred18. His knee _______________ prevented him from playing professional basketball. injury19. Other than the fact that he was born with two heads, he is a fairly _______________ sort of guy. normal20. On April 15th, 1865, American president Abraham Lincoln died after being shot in the head the _______________ night. previous。
exercise的用法和解析
exercise的用法和解析exercise的用法和解析“exercise”这个单词大家知道什么意思吗？在不同的语境中怎么运用呢？下面是店铺为大家整理了exercise的用法和解析，希望能帮到大家！一、详细释义：n.运动，锻炼 [U,C]例句：Temperance and exercise conduce to good health.节制与运动有益于健康。
例句：You must quit smoking. Most important of all, you should start taking exercise.你必须戒烟，更重要的是，你该开始运动。
练习，习题 [C]例句：Do the vocabulary exercise at the end of the chapter.做这一章末尾的词汇练习。
例句：For your homework tonight, you'll have to finish the exercise on page34.你们今晚的作业要完成第34页的习题。
【军】演习，操练 [C]例句：Praised as a heroine by many, others denounced her rescue as a staged event used by Pentagon officials as a propaganda exercise.许多人称她为英雄，也有人公开指责说林奇的获救就像一出舞台戏，被五角大楼官员们用作宣传演习。
例句：Pyongyang has accused U.S. of using the joint military exercise to provoke war.朝鲜指责美国举行联合军事演习意在挑起战争。
（特定的）活动，行动例句：It has become a threat to democracy and may render the presidential election an exercise in futility.这是对民主本质的一大威胁，可能使总统选举成为有名无实的民主活动。
徐美荣外贸英语函电Chapter2_所有知识点及课后答案
Notes1. owe…to… 将…归功于承蒙…告知你方名称和地址W e owe your name and address to the Chamber of Commerce in your city.to be indebted to … for your name and addressto come to know the name and address of your firm throughthrough the courtesy of … we come to know your name and addressto have obtained your name and address from…to have noted your name and addressto be recommended to sb. by …on the recommendation of …2. inform sb. that 通知某人某事inform sb of sth. 通知某人某事be informed that 兹通知你方Y ou are informed that …3. be in the market for 欲购；想买4. in the hope of doing 希望（后接动名词）5. ① a government-owned corporation（enterprise）国有公司/企业= a state-operated corporation / a public-owned corporation②a private corporation 私有公司/ 企业6. handle v. 经营（某种或某类商品）=to trade in / be dealing in /be in the (chemical )line（n. 行业）7. acquaint v. 熟悉了解to acquaint sb. with sth. 使某人了解某事be/get well acquainted with sth. 熟悉（了如指掌）8.on the basis of equality, mutual benefit and exchange of needed goods在平等互利，互通有无的基础上9.avail oneself to =make use of 利用10.enclose v. 随函附上11.through mutual efforts 通过共同努力= by joint efforts12.Export List 出口清单13.trade v.to trade in sth . 买卖Eg : trade in goods 货物交易to trade with sb. 与……交易；做生意trade policy 贸易政策foreign trade policy 外贸政策14.sole agent 独家代理敬启者：得知贵公司行名和地址我们要感激英国驻北京大使馆商务参赞处，他们告知我们你公司拟购买丝绸女衫。
深圳牛津九年级chapter 2 课文翻译与词组
A new hairdressing salon has opened near your home.Read this leaflet from the salon.一个新的发廊在你的家附近开业了。
读一下来自发廊的传单。
Connie’s 康妮的发廊191 Fanhua Road 繁华路191号Open 9 a.m to 10 p.m daily 每天上午9点到晚上10点开门For a wonderful hairstyle,come to Connie’s! You will be excited by our exciting hairstyles.We promise our hairstyles will make you feel on top of the world.Choose the one that is right for you.Get free advice from our experts.为了一个精彩的发型，来康妮的店吧！你将被我们令人激动的发型而激动的。
我们保证我们的发型会使你感觉最时尚的。
选择一个适合你的发型。
我们的专家免费给你建议。
What sort of hairstyle is best for me? 什么样的发型最适合我？Is your face round,square,long or heart-shaped? Short hairstyles usually suit round faces.They make the face look longer.Longer hairstyles suit square faces.They hide the angles of the face.Your hairstyle depends on your lifestyle,too.If you are a busy person,it is easier for you to look after a short hairstyle.你的脸形是圆的、方形的、长的或是心形的？短发型通常适合圆脸。
Chapter 2 词法翻译技巧
二、汉语名词的转译
他的呼吸有股大蒜的味道。 His breath smells of garlic. 他是世上一切邪恶的化身。
personify vt. to be a (perfect) example of, be the living form of (some quality) 是…的化身
Father looked at him in disapproval.
我们必须广泛利用现代科学技术的新成就。 We must utilize the achievements of modern science and technology on a wide scale.
词法翻译的一般技巧 3
变名词为动词
He personified the evil that was in the world. 计算机的灵活性比较大，因此能做很多不同的工作。
Computers are more flexible, and can do a greater
variety of jobs. 就测量的精度和速度而论，似乎还没有其他的技术能
The carpets made in our company are beautiful and magnificent.
我们进行了长期不懈的努力。
We have made unremitting efforts for it.
合并译法
二、并列成分的省略
神不知，鬼不觉 取之不尽，用之不竭 攻无不克，战无不胜 主持公道，伸张正义 场场爆满，座无虚席 洗心革面，脱胎换骨 认真读书，刻苦学习 骨肉同胞，手足兄弟 精诚团结，上下一心 secretly / stealthily
Chapter 2'
11. Reference initials
Two spaces below the author’s name and title.
The author’s initials before the typist’s
12. Enclosure(or attachment)
Two lines below the reference initials To remind the typist and receiver Spelled out (Enclosure/Attachment) Abbreviated (Enc./At.) “Enc” for one; “Encs” for more than one item Indicate the number of enclosures; identify an enclosure specifically (Enclosure: Copy of Invoice 6309)
American one Month/Day/Year British one Day/Month/Year
Choose the style of your target reader. Consider using the style of the letter you are responding to. The month written in full is preferred. A few lines below the letterhead; above the inside address
Open punctuation
No full stops or commas in the date, names, addresses, salutation, complimentary close and common abbreviations. (page 14) Use consistently in a letter.
Exercises_Chapter_2
{a,
b, c, d } :
Ω = {a, b, c, d } × {a, b, c, d } .
(a) Make a 4 × 4 table in which you write the probabilities of the outcomes. (b) Describe the event “c is one of the chosen possibilities” and determine its probability. 2.14. Consider the Monty Hall “experiment” described in Section 1.3. The door behind which the car is parked we label a, the other two b and c. As the sample space we choose a product space
Exercises for Chapter 2
2.1. Let A and B be two events in a sample space for which P ( A ) = 2 3 , P ( B ) = 1 6 , and
P ( A B ) = 1 9 . What is P ( A B ) ?
P (C D ) = 0.2 . What is P C C D ?
2.4. We consider events A, B, and C, which can occur in some experiment. Is it true that the probability that only A occurs (and not B or C) is equal to
基础会计_Ch002练习题
McGraw-Hill/Irwin
The McGraw-Hill Companies, Inc., 2007
1-8
n. Paid $925 cash for minor repairs to its drafting equipment. o. Jenna Aracel withdrew $9,480 cash for personal use. p. Paid $1,200 cash for wages to a drafting assistant. q. Paid $2,500 cash for dvertisements in the local newspaper during June.
McGraw-Hill/Irwin
The McGraw-Hill Companies, Inc., 2007
c. Purchased a portable building with $55,000 cash and moved it onto the land acquired in b. d. Paid $3,000 cash for the premium on an 18-month insurance policy. e. Completed and delivered a set of plans for a client and collected $6,200 cash.
McGraw-Hill/Irwin
The McGraw-Hill Companies, Inc., 2007
1-4
(a) (d) (h) Balance
Cash 13,325 2,000 2,300 9,340
(b) (e) (g) (i)
475 6,235 775 800
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第二章练习题
一、名词
1、需求
2、需求函数
3、供给
4、供给函数
5、均衡价格
6、需求量的变动
7、需求的变动
8、供给定理
9、供给的价格弹性10、需求的收入弹性11、需求的交叉价格弹性
12、替代品13、互补品14、恩格尔定律
二、计算
1、下表是需求函数Q d = 500 – 100P在一定价格范围内的需求表：
（1）求出价格2元和4元之间的需求的价格弧弹性。
（2）根据给出的需求函数，求P = 2元时的价格点弹性。
2、设汽油的需求价格弹性为0.2，其价格为每加仑1.2美元，试求汽油价格上涨多少会使得销售量减少10%？
2、已知某一时期内某商品的需求函数为Qd = 50 – 5P，供给函数为Qs = -10 + 5P。
（1）求均衡价格P和均衡数量Q，并作出几何图形。
（2）假定供给函数不变，由于消费者收入水平提高，使需求函数变为Qd = 60 – 5P。
求出相应的均衡价格P和均衡数量Q，并作出几何图形。
（3）假定需求函数不变，由于生产技术水平提高，使供给函数变为Qs = -5 + 5P。
求出相应的均衡价格P和均衡数量Q，并作出几何图形。
（4）利用（1）（2）（3），说明需求变动和供给变动对均衡价格和均衡数量的影响。
三、问答
1、运用供求定理分析说明“谷贱伤农”。
2、通常电力公司和自来水公司都会再三要求涨价，请以需求的价格弹性知识来说明理由。
3、随着国际原油市场价格的不断攀升，轿车的需求会有何变化？如果城市大力发展公共交通，并降低公交车、地铁的票价，驾车的需求优惠如何变化？
四、选择
1、在得出某棉花种植农户的供给曲线时，下列除哪一个因素以外其余均保持为常数？（）。
（1）土壤的肥沃程度（2）技术水平
（3）棉花的种植面积（4）棉花的价格
2、所谓低劣品、正常品之划分，是以（）为基本判断标准的。
（1）需求价格弹性（2）需求收入弹性
（3）需求交叉弹性（4）供给价格弹性
3、某月内，X商品的替代品的价格上升和互补品的价格上升，分别引起X商品的需求变动量为50单位和80单位，则在它们共同作用下该月X商品需求数量（）。
（1）增加30单位（2）减少30单位
（3）增加130单位（4）减少130单位
4、假定玉米市场的需求是缺乏弹性的，玉米的产量等于销售量且等于需求量，恶劣的气候条
件使玉米产量下降20%，在这种情况下（）。
（1）玉米生产者的收入减少，因为玉米产量下降20%
（2）玉米生产者的收入增加，因为玉米价格上升低于20%
（3）玉米生产者的收入增加，因为玉米价格上升超过20%
5、如果咖啡价格上涨，人们对茶叶的需求量上升，这说明咖啡和茶叶的需求交叉弹性（）。
（1）大于零（2）等于零
（3）小于零（4）无穷大
6、如果商品A和商品B是替代品，则A价格下降将造成（）。
（1）A的需求曲线向右移动（2）A的需求曲线向左移动
（3）B的需求曲线向右移动（4）B的需求曲线向左移动;
7、市场上某产品存在超额需求是由于（）。
（1）产品价格超过均衡价格（2）该产品是优质产品
（3）该产品是供不应求（4）产品价格低于均衡价格
8、政府对卖者出售的商品每单位征税5美元，假定这种商品的需求价格弹性为零，可以预料价格上升（）。
（1）小于5美元（2）等于5美元
（3）大于5美元（4）不可确定
9、如果价格下降10%能使买者总支出增加1%，则该种商品的需求量对价格
（1）富有弹性（2）单一弹性
（3）缺乏弹性（4）弹性不能确定
10、两种商品中若其中一种的价格变化时，这两种商品的购买量同时增加或减少，则二者的交叉弹性系数为（）。
（1）负（2）正
（1）0 （4）1
11、小麦歉收导致小麦价格上升，准确的说在这个过程中（）。
（1）小麦供给量的减少引起需求下降
（2）小麦供给的减少引起需求下降
（3）小麦供给量的减少引起需求量下降
（4）小麦供给的减少引起需求量下降
12、厂商在工资率下降的时候一般倾向于增雇工人，假如对工人的需求是缺乏价格弹性，工资率的下降将导致工资总额（）。
（1）增加（2）不变
（3）减少（4）无法确定
13、已知某种商品的市场需求函数为D=30-P，市场供给函数为S=3P-10，如果对该商品实行减税，则减税后的市场均衡价格（）。
（1）等于10 （2）小于10
（3）大于10 （4）不能确定
14、政府把价格限制在均衡价格水平以下可能导致（）。
（1）黑市交易（2）大量积压
（3）买者按低价买到了希望购买的产品数量（4）（1）和（3）
15、衡价格随着（）。
（1）需求和供给的增加而上升（2）需求和供给的减少而上升
（3）需求的减少和供给的增加而上升（4）需求的增加和供给的减少上升。