Lecture-10- Non-destructive Evaluatoin(1)
lecture
1990
Quantum confined Stark effect in quantum wells
5. Quantum optoelectronic devices
6. Quantum transport devices
1956 J. Bardeen, W. Brittain, W. Schockley: For inventing the transistors
1900 Planck’s Quantum Theory
d 2k 2k dk 2 2 ( 4 ) 2 (4 ) 2 m 2 dE
2dk 2 2 1 2m dE E
Density of States2-D 3-DFra bibliotek1-D
0
E
0
E
0
E
1 D1D
2m E
D2 D
m 2
D3 D
m 2mE 2 3
Density of States of Various Quantum Structures
Conduction band
k
Heavy hole band
2k 2 E E0 2m
Effective mass is related to the curvature of the energy band
Light hole band
2 m 2 d E dk 2
Electron’s velocity is also related to the band structure
Applications and Reaction Conditions For Restriction Enzymes
Applications and Reaction Conditions ForRestriction EnzymesStandard Restriction Enzyme ReactionsA. REACTION CONDITIONSB. SINGLE RESTRICTION ENZYME DIGESTSEach restriction enzyme has optimal reaction (assay) conditions and different conditions for long term storage. The recommended assay and storage conditions are both determined by the manufacturer to provide the user with the highest activity, best fidelity and greatest stability for each enzyme. Factors that must be considered include temperature, pH, enzyme cofactors, salt composition, ionic strength and stabilizers. Promega restriction enzyme Reaction Buffers are designed to provide the best balance of optimal activity and convenience. Promega storage buffers have been designed after accelerated and real time/real temperature stability experiments. All enzyme storage conditions are validated through our Quality Assurance re-assay program to maximize long term stability.Setting up digests with a single restriction enzyme is relatively straightforward. However, digests using multiple enzymes that have different buffer requirements may demand the use of alternative buffers and may require adjustments in the number of units of enzyme used. Table 3.1 lists the relative activities of restriction enzymes in Promega 10X Reaction Buffers. Alternatively, use the interactive search function of this guide to identifycompatible buffers. If no compatible buffer can be found a sequential reaction may be performed in which additional buffer or salt is added to the reaction before the second enzyme, or each digest may be performed sequentially using the optimal buffers. The latter option will require either a DNA precipitation or purification step after the first digest. Regardless of the type of digest performed, the addition of BSA is recommended to stabilize the enzyme and enhance activity (1) (2) .pH: Most restriction enzymes are used between pH 7.2 and pH 8.5 as measured at the temperature ofincubation. pH values outside of the optimal range may lead to star activity .Mg 2+: Commercially available restriction enzymes require Mg 2+ as the only cofactor. Restriction enzymeactivities are relatively insensitive to the Mg 2+ concentration; similar rates are observed from 5-30mM. The presence of other divalent metal ions, especially Mn 2+, may lead to star activity .Salt Concentration: Restriction enzymes are diverse in their response to ionic strength. Most are stimulated by 50-150mM NaCl or KCl while others are inhibited by salt concentrations higher than 20mM. A few enzymes prefer acetate to chloride anions. Suboptimal ionic strength or type of ion may lead to star activity .BSA: Bovine Serum Albumin is used in restriction enzyme storage buffers and is added to digestion reactions to stabilize the enzyme. BSA can protect restriction enzymes from proteases, non- specific adsorption and harmful environmental factors such as heat, surface tension and interfering substances. Typically, the addition of0.1mg/ml BSA will result in a 1.5 to 6-fold enhancement of enzyme activity. The Acetylated BSA provided with Promega's restriction enzymes has been modified and extensively tested to ensure that no degrading activities are present.Glycerol: Glycerol is added to restriction enzyme storage buffers to prevent freezing at -20°C. Repeatedfreeze/thawing of restriction enzymes can reduce their activity. Some restriction enzymes show reducedspecificity, or increased star activity , when the glycerol concentration in the final reaction is higher than 5% although many have normal specificity at glycerol concentrations as high as 10%.Incubation Temperature: Most restriction enzymes show maximum activity at 37°C. A few enzymes require higher or lower temperatures for optimal activity (e.g., Taq I, 65°C; Sma I, 25°C). For incubations greater than 1 hour with high temperature enzymes, cover the reactions with a drop of mineral oil to prevent evaporation. Generally, the incubation temperature for the enzyme reflects the growth temperature of the bacterial strain from which it is derived. For enzymes that have temperature optima other than 37°C, Promega provides information on percent activity at 37°C on the Product Information sheet that is packaged with each enzyme. This type of information is particularly useful when performing double digests.Volume: Viscous DNA solutions inhibit enzyme diffusion and can reduce enzyme activity. DNA concentrations that are too dilute can fall below the K m of the restriction enzyme and also affect enzyme activity. Volumeconsiderations must take into account final ionic strength and must result in glycerol concentrations no higher than 5-10% in order to avoid star activity. Reaction volumes of 10-50µl per microgram of DNA are recommended.An analytical restriction enzyme reaction is usually performed in a volume of approximately 20µl on 0.2-1.5µg of substrate DNA using a 2- to 10-fold excess of enzyme over DNA, based on unit definition. Use of an unusually large volume of DNA or enzyme may give aberrant results. Caution should be exercised to prevent higher than1.Under sterile conditions add the following components, in the order stated, to a sterile microcentrifugetube.2.Mix gently by pipetting. Centrifuge briefly at 12,000 x g in a micro centrifuge to collect the contents at thebottom of the tube.3.Incubate at the optimum temperature for 1-4 hours. 4.Add 4µl of Blue/Orange 6X Loading Dye (or another appropriate DNA loading buffer), and proceed to gelanalysis.C. MULTIPLE RESTRICTION ENZYME DIGESTSe the optimal buffer supplied with one enzyme if the activity of the second enzyme is acceptable in thatsame buffer. Alternatively, acceptable activity for both enzymes may be achieved by using another ofPromega’s 4-CORE ® 10X Buffers(Cat.# R9921). If one of the enzymes has less than 75% activity in thechosen buffer, the reaction time or the number of units of enzyme used may need to be increased. Beaware of possible star activity under non-optimal reaction conditions (see Table 3.1 or use the interactivesearch function of this guide to identify compatible buffers).2.Choose an isoschizomer or neoschizomer with more compatible buffer requirements. 3.Perform a single digest with the first enzyme then inactivate that enzyme. Add the ingredients necessaryfor the second digest then add the second enzyme. For example, use a lower salt buffer and enzyme first,then inactivate the first enzyme, add enough salt to achieve the concentration required for the seconddigest, and add the second restriction enzyme.D. EXPERIMENTAL CONTROLSnormal concentrations of EDTA and glycerol. The following is an example of a typical analytical single restrictionenzyme digestion:Sterile, nuclease-free water14µl Restriction enzyme 10X buffer2µl BSA, Acetylated (1mg/ml)2µl DNA sample 0.2-1µg, in water or TE buffer1µl Restriction enzyme, 2-10U1µl Final volume 20µlLarger scale restriction enzyme digestions can be accomplished by scaling this basic reaction proportionately.If all of the restriction enzymes in a multiple digest have the same optimal buffer, setting up the digest isstraightforward. However, when this is not the case, several options are available.Note: Perform each digest sequentially using the optimal buffers. This will require either a DNA precipitation orpurification step after the first digest. Although this procedure involves more steps than those listed above, insituations where options 1-3 are not satisfactory, it may be the best alternative.Some common controls used for restriction enzyme digestion and gel analysis are given in Table 2.1.Table 2.1. Restriction Enzyme Reaction ControlsRestriction Enzyme Digest ControlsControl: Untreated DNA controlStrategyPurpose DNA is loaded on gel with no treatment otherthan the addition of loading buffer. Shows the integrity of the DNA starting material. Nicked, linear and supercoiled forms of plasmid DNA are normally seen in untreatedsamples.Control: No enzyme ControlStrategyPurpose A mock digest is run parallel with theexperimental digest, except that no enzyme isadded. The missing volume is made up withpares DNA digests with and without enzyme. Detects changes that may occur independent of enzyme such as exonuclease contamination in the DNA or in one of the reaction components.Control: Enzyme activity checkStrategy PurposePerform a control digest using the unitdefinition DNA (usually lambda) andconditions as described in the PromegaProduct Information sheet.Confirms enzyme activity.Control: DNA substrate control and general enzyme digest control Strategy PurposeSet up the following parallel digests:1.Perform a digestion as described inthe unit definition for the enzyme butusing the experimentally derived DNAinstead of control DNA. Adjust thenumber of enzyme units based onrecognition site density.2.Perform the experimental digest,replacing the experimental DNA withthe same quantity of commercialquality DNA (usually lambda DNA).Adjust the number of enzyme unitsbased on recognition site density. Compares activity of the enzyme under experimental conditions using standard DNA and experimental DNA under standard conditions. Tests for possible problems with substrate DNA such as impurity, missing recognition sites, methylation, etc. Can be used to assay for the function of other reagents used in the enzyme digest. If an inhibitor is suspected in the DNA solution, a set of digests comparing experimental DNA, control DNA and a combination of the two may also be performed. In most cases, the presence of an inhibitor will "poison" the control reaction when both are combined.Gel Analysis ControlsControl: One molecular weight (MW) markerStrategy PurposeOne or two lanes of an electrophoresis gel should always be devoted to size standards and used for comparison with unknowns. This assures that a standard exists for:1.Determining the distance samples have run in the gel.2.Measuring the sizes of unknown fragments.3.Repeatedly seeing a familiar pattern of known andstandardized MW.Control: Two different MW markersStrategy PurposeTwo different size markers provide much more information than one. Two sets of data points give greater accuracy during graphing of data points for MW measurements (by comparison with the mobility of the standards). Lane-to-lane variation may also be detected if two standards are used but they migrate differently. A greater range of size standards permits more accurate size estimation, and allows identification of conformational effects on mobility as well as electrophoretic variability.Anomalous mobility due to differences in the quantity of sample loaded may also be detected.Control: Load two different quantities of the same MW marker on the gel Strategy PurposeMass per band control: Loading two different quantities of the same size marker will yield important information about mobility shifts due to mass per band differences.Allows detection of mass effects on mobility. Also may show lane-to-lane variation during gel electrophoresis.Control: Salt effects controlStrategy PurposeRun markers beside unknown with and without the salt contained in the experimental digest.Detects any gel retardation that may occur due to the presence of high salt concentrations in sample.Control: Markers of known mass are run in a dilution series1.Williams, R., Kline, M. and Smith, R. (1996) BSA and restriction enzyme digestions. Promega Notes 59,46.2.Lepinske, M. (1996) BSA and restriction enzyme digestions. Promega Notes 60, 28.Restriction Enzyme ActivityStrategyPurpose Bands of similar MW are chosen in markerand experimental lanes. The mass of theband in question is compared to a controlbased on its staining intensity. It is crucial thatmany dilutions are run side-by-side in order toachieve the most accurate visual comparison. The quantity of an unknown DNA sample may be assessed in this manner or used to confirm a result obtained by spectrophotometry.References Back to topRestriction enzymes differ in their reaction kinetics. As a result, variations from the recommended incubationtime, number of units used, substrate amount, and/or total reaction volume should be considered carefully toensure complete digestion. The following table gives an indication of the activity of Promega blue/white cloning-qualified and genome-qualified restriction enzymes under varying reaction conditions. Variations in the number ofenzyme units used and the reaction incubation times were tested. In each case the reaction volume (50µl) andthe amount/type of DNA substrate (1µg) were the same as that used in the unit definition assay. Incubation timefor the unit definition assay is one hour.Table 2.2. Restriction Enzyme Activity under Nonstandard Units and Incubation Time Conditions.EnzymeReaction Time and Number of Units Used 15 min.4 units 15 min. 2 units 15 min. 1 unit 30 min. 2 units 1 hr 1 unit 2 hr 0.5 units 4 hr 0.25 unitsAatII C I I C C C CAccI C C C C C C IAcc65I C I I C C II ApaI C I I C C C CAvaI C C I C C C CBamHI C C I C C I IBbuI C I I I C C CBcl I C I I C C C CBgl I C I I C C C CBstXI C I I C C C CBstZI I I I C C C CClaI C I I C C C CCspI C I I C C I ICsp45I C I I C C CC Eco52I C I I C C I IEcoRI C I I C C C CEcoRV C I I C C CC Hi II C I I C C C CRestriction Enzyme Substrate ConsiderationsA. SUBSTRATE SOURCE AND STRUCTUREHincII C I I C C C CHindIII C I I I C C CKpnI C I I C C C CMluI C I I C C C CNcoI C I I C C C CNheI C I I C C C CNotI C I I C C C INsiI C I I C C C CPstI C I I C C C CSacI C I I C C C CSacII C I I C C C CSal I C C C C C C ISfiI C I I C C C CSmaI C C I C C C CSpeI C I I C C I ISphI C C C C C I ISspI C I I C C C CStyI C I I C C I IXbaI C I I C C C CXhoI C I I C C C CXmaI C I I C C C C"C" indicates complete cleavage; "I" indicates incomplete cleavage for the units and incubation times shown. Back to topSubstrates commonly used for restriction enzyme digestion include phage DNA, plasmid DNA, genomic DNA,PCR products and double-stranded oligonucleotides. The concentration of the DNA sample can influence thesuccess of a restriction digestion. Viscous DNA solutions, resulting from large amounts of DNA in too small of avolume, can inhibit diffusion and can significantly reduce enzyme activity (1) . DNA concentrations that are toolow also may inhibit enzyme activity (see Substrate Quality ). Typical K m values for restriction enzymes arebetween 1nM and 10nM, and are template-dependent (2) . Recommended final DNA concentrations for digestionrange from 0.02-0.2µg/µl. Substrate structural variations, concentration and special considerations are discussedbelow according to DNA type.Lambda DNA: Lambda DNA is a linear DNA that is an industry standard for the measurement and expression ofunit activity for most restriction enzymes. In general, one unit is sufficient to cut 1µg of lambda DNA in 1 hourunder optimal reaction conditions in a reaction volume of 50µl. In lambda DNA, the cos ends, (12-base,complimentary, single-stranded overhangs at the end of each molecule) may re-anneal during digestion. Thiscan give the appearance that digestion is incomplete. To avoid this problem, heat the DNA at 65°C for 5 minutesprior to electrophoresis to melt ends that have annealed.Plasmid DNA: Circular, supercoiled plasmid DNA typically ranges from 3-10kb in size. Compared to linear DNA,plasmids often require more units of restriction enzyme for complete cleavage due to the supercoiling (1) or thetotal number of sites to be digested (see Recognition Site Density ). See Digestion of Supercoiled Plasmid DNAfor information on the relative units needed for complete cleavage of a typical plasmid vector with commoncloning enzymes. If a supercoiled plasmid is first linearized with another restriction enzyme or relaxed with topoisomerase, less enzyme may be needed for digestion.Genomic DNA: Digestion of genomic DNA can be difficult due to methylation and viscosity. If methylation is a concern, consider using isochizomers with different methylation sensitivities (see Methylation Sensitivity of Isoshizomer/Neoschizomer Pairs). Viscosity can be adjusted by increasing the reaction volume. Genomic DNA often digests more efficiently when it is diluted to a minimum concentration of 10µg per 50-200µl. If this is not possible, heating the DNA at 65ºC for ten minutes prior to the addition of the restriction enzyme can enhance activity (3) . Addition of spermidine to final concentration of 1-5mM also has been reported to increase enzyme activity in the digestion of genomic DNA (4) . Addition of BSA to restriction digests at a final concentration of0.1mg/ml may also improve enzyme activity.PCR Products: PCR-amplified DNA may be digested with restriction enzymes that have recognition sequences within the amplified sequence or in the primer regions. The number of enzyme units needed must be balanced with the total number of sites to assure complete cleavage. Longer incubation times may be required to ensure complete digestion. Enzymes with low overdigestion values (<12 units/16 hours) should be avoided in overnight digestions, as star activity or trace contaminants present in these enzymes may lead to problems. Consult the Promega Product Information sheet for the overdigestion value of the enzyme. For many common restriction enzymes, acceptable activity is seen in PCR buffer, although digestion after amplification may not result in the expected compatible ends due to residual polymerase activity (5) . Digestion near the end of a PCR product may also present problems. Restriction enzymes require varying amounts of flanking DNA around the recognition site, usually 1-3 bases but occasionally more (See Digestion of Sites Close to the End of Linear DNA). If an oligonucleotide primer is designed with a cut site that is too close to the end of the DNA, the site may cut poorly or not at all. Since it is very difficult to assay for cutting near the end of DNA, the effectiveness of compensation with extra enzyme units or increased incubation time is difficult to determine. Use of proofreading enzymes in PCR may also complicate the situation as these enzymes are capable of degrading the 3´ ends of amplimers, interfering with complete digestion by restriction enzymes. The use of high dNTP concentrations and immediate cooling to 4°C after PCR will reduce such degradation. Another reason for incomplete digestion of PCR fragments may be primer dimers. If the restriction site is built into the primer, primer dimers will contain a double-stranded version of the site, usually in vast molar excess over that of the desired target PCR fragment. This problem can be easily avoided by purifying the PCR fragment prior to restriction enzyme digestion using the Wizard® PCR Preps DNA Purification System (Cat.# A7170).Double-Stranded Oligonucleotides: Many of the same considerations for PCR products apply to the digestion of double-stranded oligonucleotides. In this case high densities of recognition sites per unit of mass can be present and the site may also be near the end of the DNA molecule. Again, longer digestion times and/or more enzyme may be needed. Enzymes with a low overdigestion specification (12 units/16 hours) should be avoided in overnight digestions.Single-Stranded DNA: Cleavage of single-stranded DNA, although at a greatly reduced rate compared with double-stranded DNA, has been reported for a few restriction enzymes (6) . Studies have shown, however, that several restriction enzymes that appear to cleave single-stranded DNA actually recognize folded-back duplex regions within the single-stranded genomes (e.g., M13, f1, single-stranded phiX174) (7)(8) . Therefore, these enzymes are not digesting single-stranded DNA, rather individual sites that are in the duplex form.DNA-RNA Hybrids: Digestion of DNA-RNA hybrid molecules has been described for several restriction enzymes (AluI, EcoRI, HaeIII, HhaI, HindIII, MspI, SalI, ThaI) (9) . In these cases, the DNA strand of the hybrid was digested in the identical place as duplex DNA. Digestion required 20 to 50-fold higher enzyme levels than those needed for duplex DNA. It is possible but not proven that the RNA was also cleaved with large excesses of enzyme.Influence of Flanking Sequence: The sequences flanking the restriction enzyme recognition sequence can influence the cleavage rate of many restriction enzymes although the differences are usually less than 10-fold. A small number of enzymes (e.g., NaeI, HpaII, SacII, NarI, EcoRII) exhibit more pronounced site preferences and are designated Type IIe. See Site Preferences and Turbo™ Restriction Enzymes for further information.Methylation: Methylation of nucleotides within restriction enzyme recognition sequences can affect digestion. Methylation may occur as 4-methylcytosine, 5-methylcytosine, 5-hydroxymethylcytosine or 6-methyladenine in DNA from bacteria (including plasmids), eukaryotes and their viruses. The sensitivity, or lack thereof, to site-specific methylation, is known for many restriction enzymes (10) . Often, isoschizomers differ in their methylation sensitivity. Refer to Table 3.6 for further information.B. SUBSTRATE QUALITYGeneral Quality of the DNA Substrate and Effect on Digestion: Highly purified DNA is required for efficient restriction enzyme digestions. Contaminants commonly used during the purification of DNA such as protein, phenol, chloroform, ethanol, EDTA, SDS, CsCl and NaCl may interfere with restriction enzyme performance if not eliminated prior to digestion (1) . Organic solvents may denature the enzyme and additional salt contamination may decrease enzyme activity. Because contaminants are usually dose dependent, inhibitory effects will increase with the volume of DNA added to the digestion reaction. Protein contaminants in DNA can include nucleases that are activated by the addition of Mg2+ or salt in the restriction enzyme buffer. The presence of such nuclease activity will result in degradation of the substrate DNA, evidenced upon electrophoresis as a smear or a loss of DNA compared with a control sample of untreated DNA. Other potentiali i l d DNA bi di i hi h i ll i f i h h bili f hC. RECOGNITION SITE DENSITYcontaminants include DNA binding proteins, which may sterically interfere with the ability of the enzyme toefficiently find its recognition site and/or retard electrophoretic mobility of the restriction fragments.DNA samples are often stored in Tris-EDTA (TE) buffer since EDTA inactivates most nucleases that co-purifywith DNA by chelating the divalent cations required for their activity. However, restriction enzymes requiredivalent cations for activity and may be inhibited if too much EDTA is present in the final reaction. Lowconcentrations of EDTA (less than 0.05mM) introduced into the restriction enzyme reaction as in the DNAstorage buffer do not substantially affect restriction enzyme activity.Some of the most commonly encountered problems for specific DNA preparations are discussed below andsuggestions for optimizing the performance of restriction enzymes on these substrates are provided.Miniprep DNA: DNA purified from minipreps can be of poor quality due to contaminants such as phenol,chloroform, protein or RNA. In addition, some bacterial strains used to amplify plasmid DNA (e.g., HB101)contain a greater amount of nuclease than others (e.g., JM109). Such enzymatic contaminants may only becomeapparent when activated by the Mg 2+ and salt present in restriction digest buffers. Phenol/chloroform extractionmay be required to remove these contaminants even after CsCl purification. Dialysis and/or multiple ethanolprecipitations with 2.5M ammonium acetate and drying can remove many of the interfering substancesintroduced during purification. Ammonium acetate, which is a volatile substance, has unique and beneficialproperties compared with other salts used for nucleic acid precipitation, but must be used in substantially higherconcentrations (1) .Alternatively, the Wizard ® Plus SV Minipreps DNA Purification Systems (Cat.# A1330) provide an easy andeffective way to isolate and purify DNA, free of salt or macromolecular contaminants. The addition of spermidineto a final concentration of 1mM and/or BSA to a final concentration of 0.1mg/ml can also improve digestion ofpoor quality miniprep DNA.Genomic DNA: Genomic DNA frequently contains more contaminants than plasmid DNA. Best results areobtained when the absorbance ratios at A 260/A 280 are at least 1.8. Spermidine can be added to a finalconcentration of 1mM and/or BSA to a final concentration of 0.1mg/ml to improve digestion of poor qualitygenomic DNA. For further information see Digestion of High Molecular Weight DNA .Genomic DNA Embedded in Agarose plugs: Pulsed field gel electrophoresis permits the resolution ofextremely large DNA fragments. Genomic DNA purified by traditional techniques can contain double-strandedbreaks due to mechanical shear forces. Such breaks can be a source of background in megabase mapping offragments of 50-1000kb. To avoid this, mammalian, bacterial and yeast cells can be embedded in agarose stripsand the cells lysed and treated with proteinase K in situ (11) . Most restriction enzymes can cut DNA embeddedin agarose provided that more enzyme and longer incubation times are used. A good rule of thumb is to use 5-10units of enzyme per microgram of DNA and to avoid using restriction enzymes with low overdigestion values(<20 units/16 hours), which can cause problems during longer incubations with excess enzyme. For furtherinformation, refer to Digestion of High Molecular Weight DNA .Genomic DNA Purified From Blood. The anti-coagulant used during blood collection can affect the ability ofrestriction enzymes to completely digest DNA. Use EDTA as an anti-coagulant rather than Heparin, which canbind tightly to the enzyme and interfere with digestion. The absorbance ratios at A 260/A 280 should be at least 1.8,indicating that protein has been removed efficiently. A number of rapid DNA purification protocols have beenwritten that do not require separation of white cells from red cells (12) (13) . These techniques can yield goodquality DNA from small volumes of blood, but the DNA obtained after scale-up may be of poorer quality. Forlarger blood samples, a technique that separates white blood cells from red blood cells, such as pelleting redblood cells through a Ficoll ® gradient, is recommended prior to DNA purification.Promega offers the Wizard ® Genomic DNA Purification Kit (Cat.# A1120) for the isolation of genomic DNA fromwhite blood cells (with reagents/protocol for removal of red cells), tissue cultured cells, animal tissue, plant tissueand Gram-positive and Gram-negative bacteria. DNA purified with this system is suitable for digestion withrestriction enzymes.PCR Products: Contaminants in PCR such as salts, glycerol, and primer dimers can inhibit restriction enzymeactivity. The Wizard ® PCR Preps DNA Purification System (Cat.# A7170) provides a reliable method forpurification of double-stranded PCR-amplified DNA from any salts or macromolecular contaminants.Restriction enzyme activity units are usually defined based on a one-hour digest of 1µg of lambda DNA. Whendigesting other substrates, adjustments may be needed based on the amount of substrate, the number ofrecognition sites per molecule and the incubation time. The following table illustrates the effect of differences insubstrate recognition sites per molecule for Eco R I while keeping the substrate mass and incubation timeconstant.Table 2.3. Differences in Substrate Recognition Sites for EcoR I.DNA Substrate BasePairs Picomoles in 1µg*Cut Sites (EcoRI)Picomoles Cut Sites Units Needed。
Lecture 10 The Passive Voice in English-Chinese Translation
2. Chinese Sentences without Passive Labels 这座桥将在今年年底建成。 The construction of the bridge will be completed by th是在这样的基础上提出来的。 On such a basis has the question of the intellectuals been raised.
4. Translation of Some Idiomatic Chinese Expressions 众所周知，火药是中国古代的四大发明之一。 It is well-known that gunpowder is one of the four great inventions of the ancient Chinese people.
据谣传，那场事故是由于玩忽职守而造成的。
It is rumored that the accident was due to negligence.
4. Translation of Some Idiomatic Chinese Expressions 有人认为 It is considered that
But one hundred years later, the Negro is still not free. One hundred years later, the life of the Negro is still sadly crippled by the manacles of segregation and the chains of discrimination.
Exercises:
The increasing speed of scientific development will be obvious if one considers that TV, space craft, and nuclearpowered ships, which are taken for granted now, would have seemed fantastic to people whose lives ended as recently as 1920. 电视机、宇宙飞船和核动力潜艇对今天的人们来说不 是什么新鲜事物，但对于生活于20世纪20年代以前的人来 说，却似乎是不可思议的东西。考虑到这一点，科学的发 展速度之快也就显而易见了。
新视角研究生英语读说写第二册1-8课汉译英答案
Chinese-English1. 那位教授很可能在他唯一的学生缺席的情况下对着空空的教室讲了一课。
The professor might probably have delivered his lecture to the empty classroom in the absence of his solitary student.2. 现行的教育体制遭到了公众的批评，公众已经开始意识到这种体制给学生带来的危害。
The present educational system has been under attack from the public, who have begun to realize the harm the system has done to students.3. 老师告诉这些大四学生他每次都会点名，因为这门课是必须要听的。
The professor told those seniors that he would take attendance every time because attendance at this course was compulsory.4. 我真想参加你的乔迁聚会。
但是很抱歉我无法去, 因为我有一大堆事情要做。
I’d love to go to your housewarming party, but I’m sorry I can’t make it because I’ve got a stack of things to do.5. 中学辍学的年青人可以上夜校或通过电大和函授课程恢复他们的学业。
Youths who dropped out of middle school can resume their studies at night school or through television and correspondence courses.6. 她不喜欢那位著名作家的讲座，但她为了在讲座后得到他的签名还是耐着性子听完了。
华工网络教育大学英语B（二）·第二次平时作业客观题
华工网络教育大学英语B（二）·第二次平时作业客观题第一篇：华工网络教育大学英语B(二)·第二次平时作业客观题华工网络教育大学英语B（二）·第二次平时作业客观题1.― Excuse me, but can you tell me the way to the airport?― _______A)Don’t ask that.B)Go straight down this street.Turn left at the first traffic lights.You can’t miss it.C)No, I can’t say that.D)No, you’re driving too fast.参考答案：B 2.―_______― Just over there at the second corner.A)Hello, sir.Tell me where the station is.B)Excuse me, could you tell me where the station is, please?C)Good afternoon, sir.The station , please.D)Pardon, sir.Can I get to the station, please?参考答案：Bsomething in what he suggested.参考答案：D14.Choose the best answer for each of the following sentences.Can you find out _______her pen?A)where Alice had put B)where had Alice putC)where Alice has put D)where has Alice put参考答案：C15.You can’t imagine _______when they received these gifts.A)how they were excited B)how excited they wereC)how excited they have D)they were how excited参考答案：B16.I will give this book to _______wants to have it.A)whomeverB)whoever C)whatever D)wherever参考答案：B 3.Prices of daily goods _____online can be lower than store prices.A)are bought B)bought C)been boughtD)buying参考答案：B 4.Mr.Smith, _______ of the _______ speech, started to read a novel.A)tired;boring B)tiring;bored C)tired;bored D)tire;boring参考答案：A 5.The net bar, _______last year, is very popular among the students in this school.A)open B)opening C)having opened D)opened参考答案：D 6.I’m going to have my car _______this afternoon.A)to be fixed B)to fix C)fixed D)fixing参考答案：C 7.The girl _______under that tree is my sister.A)is sitting B)sits C)sat D)sitting参考答案：D 8.Let’s make it round 8 o’clock._______A)You’re all right.B)Yes, I can.C)Please don’t.D)W ould some time later be convenient?参考答案：D 9.Choose the best answer for each of the following sentences.Jane said, “Are you tired?” = Jane asked me _______.A)if I was tired B)if was I tired C)if I am tired D)if am I tired参考答案：A 10.John said, “May I go with you?” = John asked me _______.A)if I might go with you B)if he might go with youC)if he might go with me D)if he might go with John参考答案：C 11.The teacher said, “What are you thinking about?” = The teacher asked me _______thinking about.A)what were you B)what you were C)what I was D)what was I 参考答案：C 12.When asked whether he had seen Jim, Tom answered, “_______”A)Yes, I have.B)Nor have I.C)Certainly, he had seen him.D)Of course, I will.参考答案：A 13.What do you think of his suggestion? _______A)It’s not the case.B)I don’t think so.C)I believe so.D)There’s17._______you don’t like him is none of my business.A)WhatB)Who C)That D)Whether参考答案：C18.We must do well _______the boss assigns us to do.A)thatB)whatever C)whichever D)those参考答案：B 19.I have not found my book yet.In fact, I’m not sure _______I couldhave done with it.A)if B)whether C)how D)what参考答案：D20._______is a fact that English is accepted as an international language.A)What B)This C)That D)It参考答案：D21.Choose the best answer for each of the following sentences.I shall never forget those days _______I lived in the country with thefarmers.A)that B)when C)which D)what参考答案：B22.Can you tell me the name of the city _______you visited last summer?A)what B)where C)/ D)it参考答案：C23.Is this the restaurant _______?A)which you work B)in which you work C)for which you work D)where you work in参考答案：B24.That tree, _______branches are almost bare, is a very old one.A)whose B)which C)that D)it参考答案：A25.This is one of the books that _______worth reading.A)isB)are C)has D)have参考答案：B第二篇：大学英语B·平时作业2017秋华工网络教育答案大学英语B（一）·英语作文My Dream Everyone has his own dream.Some want to be doctors.Others hope to be scientists.My dream is to become a teacher.Teachers can not teach us many things at school, but they do their best to teach us how to learn.Thanks to them, we learn knowledge.And at the same time, we learn how to live a happy life.They spend most time on their students.They are great in my eyes.I hope to be a teacher because I admire teachers.I know it is not easy to make my dream come true.But I decide to study harder from now on.I am sure my dream will come true.My Happiness in LifeMy sunshine in my lifeHow should I describe my life?It's a golden age because we have an interesting and colorful life.If you enter any classroom when you do self-study off school,you will find that students are making good use of their time.Some of the students are busy reading English or Chinese.Now we are studying hard,because study comes first now.In our PR class,we are no longer bookworms,but because so lively that we feel just like fish in the water.We hope to enter our ideal universities or colloeges after we graduate from our school for we will become trans——century talents in the near future.I am sure,in the future,when we look back on our lives today,we must can feelproud of ourselves!We Love a Green World We visited the first scenic area isdesert botanical garden.“Wow, there is lot of odd shape of cactus!” I was attracted by the shape of a cactus.A small spherical shape,pillars, and human.At this time, my heart had a question: why not cactus leaves? To solve the teacher in my heart: doubt them is their small body leaves.I excitedly said: “the original them small thorn, is their leaves!” Cactus is due to the adaptation of desertlife and maintain the loss of water is not only no leaves.From the desert botanical garden, we came to the second scenic spots: fossil forest,which is full of high fossil trees.I put a tallest tree with tree fossils than a tree fossilswere much higher than those of the tree now.We also went to many scenic spots, the scenic spot has green.This autumn I learnedmuch knowledge, let me find the nature has many secrets waiting for me to explore, we love the green world.第三篇：华工网络教育《刑法学》平时作业一、名词解释1.从旧兼从轻原则答：从旧兼从轻原则是一个刑法适用原则，指除了对非犯罪化（除罪化）、弱化惩罚或有利于行为人的规定之外，刑法不得有溯及既往的效力。
大学生英语竞赛(NECCS)B类英语专业决赛真题2018年
C.Room 108.D.Room No. 8.C[听力原文]W: Excuse me, Jack. Do you know the examination room of Mathematics taught by Mr. Brown?M: I remember Mr. Brown told us the exam would take place in Room 108 of the No. 4 Teaching Building. W: Room 108, isn't it 801?M: No, I'm confident of my memory.Question: Where does the exam take place?[解析] 对话中女士问男士布朗先生教的数学班在哪考试，男士回答说在第四教学楼的108房间。
女士表示质疑后男士再次确认表明教室就是在108房间。
4.A.Wednesday.B.Monday.C.Friday.D.Tuesday.A[听力原文]M: There is a job which suits you perfectly. A receptionist in the new Sports Centre.W: Sounds good. Then what about the working hours?M: Er, you need to work in the mornings, about three mornings every week-Monday, Wednesday and Friday morning.W: Okay. I'll apply for it.Question: What's the second working day of each week for the woman?[解析] 对话中女士询问她的工作时间后，男士回答女士说她要在每周一、周三和周五早上工作，因此女士每周工作的第二天为星期三。
英语视听_东北师范大学中国大学mooc课后章节答案期末考试题库2023年
英语视听_东北师范大学中国大学mooc课后章节答案期末考试题库2023年1.What has the woman been preparing for?参考答案:Writing a term paper on Hamlet.2.What does the woman think is very surprising?参考答案:Jack Kilby is not very well-known.3.单元测试四音频How is the woman going to travel?参考答案:By train.4.According to the man, at what time could the woman arrive at the station?参考答案:10:40.5.单元测试一音频Where does the conversation probably take place?参考答案:At home.6.What information about train services does the woman provide?参考答案:The direct train going to London will leave in 2 hours.7.What does the man mean?参考答案:He understands why it’s getting difficult to find a parking space.8.单元测试二音频Why didn’t the man go to the party?参考答案:He had to handle something unexpected.9.What does the woman say about the bus services?参考答案:The No. 28 bus doesn’t go to her house anymore.10.What does the man say about music?参考答案:He doesn’t know how to appreciate music.11.What does the man say about Charlie Chaplin’s films?参考答案:Charlie Chaplin’s films are very creative.12.Which invention does the man think changed the world most?参考答案:The light bulb.13.What are the two speakers talking about?参考答案:Their different college lives.14.单元测试三音频Why didn’t the man go to the concert?参考答案:He was too sick to go.15.What can we learn about Jennifer’s job interview?参考答案:She didn’t feel like taking about the interview.16.What are the speakers talking about?参考答案:Meeting former classmates.17.What will the man probably do?参考答案:He will give the bicycle back right now.18.When you understand the grammar of a language, you can understand manythings yourself, (9) having to ask a teacher or look in a book.参考答案:without19.It is (8) to think of grammar as something that can help you, like a friend.参考答案:important20.Children start to speak before they even know the word “grammar”. But ifyou are (7) about learning a foreign language (as opposed to your nativelanguage), the long answer is “yes, grammar can help you to learn a languag e more quickly and more efficiently.”参考答案:serious21.Do we need to study grammar to learn a language? The short answer is “no”.Very many people in the world speak their own, (6) language without having studied its grammar.参考答案:native22.What we call “grammar” is simply a reflection of a language at a (5) time.参考答案:particular23.No commonly spoken language is fixed. All languages change (4) time.参考答案:over24.But languages did not start like that. Languages started by people making (3) ,which evolved into words, phrases, and sentences.参考答案:sounds25.If we use the word “rules”, we suggest that somebody (2) the rules first andthen spoke the language, like a new game.参考答案:created26.Part 3 PassageListen to a short passage THREE times. Fill in the blanks withthe exact words you hear.Grammar Is Your FriendGrammar is the system of a language. People sometimes (1) grammar as the “rules” of a language; but in fact no language has rules.参考答案:describe27.What is the man’s attitude toward h is current assignment?参考答案:He is optimistic that he will learn to appreciate the play he isresearching.28.How does the woman think of the play performed on the stage?参考答案:Funny but moving.29.Which of the following is NOT included in the man’s assignments?参考答案:To watch the video of the play he’s required to read.30.When was the play Happy Strangers written?参考答案:In 1962.31.Part 2 Long conversationListen to a long conversation TWICE and choose thebest answer to each question you hear. Questions 6-10 are based on theconversation.Why does the man need the woman’s assistance?参考答案:He wants to know where to find the old newspaper reviews about a play.32.What can we learn from the conversation?参考答案:The woman’s family will have a holiday on the beach.33.What problem are the man and woman talking about?参考答案:They don’t have enough money for a vacation.34.What does the man think of the woman?参考答案:She has bought too many gifts.35.What is the result of the discussion?参考答案:They have agreed on when to have another discussion.36.期末考试音频Part 1 Short conversationsListen to five short conversationsTWICE and choose the best answer to each question you hear.Why can’t the man leave on Thursday?参考答案:Because he will have a visitor.37.So think of grammar as something good, something (10) , something that youcan use to find your way like a signpost or a map.参考答案:positive。
华北水利水电大学英语视听说慕课答案
华北水利水电大学英语视听说慕课答案Whether English should be removed from the CollegeEntrance Examination and give your reason?What is theaim of the reform?What are advantages and disadvantages?Are you agree with the reform that Samaritan见义勇为[s?'m?ritn]will be taken into consideration in favorable scoringpolicy in college entrance examination and please give your reason.教科书/作业答案Unit1Basic listening practice:CDABCListening in:task 1:While the man is wondering why the woman is suddenlygettingexcellentmarks,she saysshe read an article on studing and remembering.It talksabout principleslike "Mental Visulization",that is,creatinga picturein one's mindof what is to be remembered.This reminds the man of the principle "Association',Consolidation”new material into what one has already learned sixteen"Distributed Practice'shorter several days a muscle eexerciseTask3:1A 2.C3.D 4.B 5.DFurther listening:task 1:ABDDCcarrots,eggs,bananas,and milklost keys(2)a giant carrot and a banana hanging from ita giant milk carton pouring milk over the(4)carrot and bananaan egg-shaped UFO flying across the skyThe sound of the keys might remind you of6)having placed them in a drawer.The cold touch of the keys might remind you (7)of them in your jacket.Further listening and speaking:Where did the professor gotrue entertained particular retired pour openedby staying overnight,he did not need to go out in the bad weather.washing the dishes after supper,the forgetful professor disappeared because he was going to stay there overnight,he had gone home to get his pajamas andtoothbrush.Unit2:Basic listening practice:CDBDAListening in:task 1:Seeingthat Jennyhas bought the books for the biology class,Harrison saysnobody does much on the first day becauseit stilladd-drop,whichmeans students arehangingfrom class to class.Jenny knows the professoreally good.But Harrison warns her that the professor is good,only if students amand-workers forhe expectsa lot.After class,Jenny admits thathalf of what the professor said went over her head andHarrison assuresher that a lot of what the professor said explained in the readingWhen Jenny asks to borrow Harrisonnotes he says“on problem”,for they donhave classuntil Wednesday.Finally,Harrison sayparticipation in the discussionat theseminar is an important part of the education there.Task2:TFFFTTask3:1B 2.C3.D 4.A 5.DFurther listening:task 1:BACDDFurther listening and speaking:Prince William in ChileScriptWhat goes into a prince education today?For Britain 'Psnce William,natureplayed an importantrole in his education this last winter,as the future king went on a10-week expedition in Chile with Raleigh International.The experiencewas a very different one for the prince.He kayakedin ocean fjords,tracked a rare deer,and was stranded on a beach durisitramn.He also got used to sleeping on the ground-at times in a room filled with 16 peopleand living insimple conditionsThose who took part,called"volunteeostributedkaotd learned.The princehelped locals build wooded walkways and buildings,and taught English toschoolchildren.He was describedby other volunteers as hardworking,humble,and laid-back.As onesaid,"He struck a really gbatancebetween working hard and having fun …gettingon with everyone,and taking on thteam spirit.The prince said he liked being treated as an "equal by other volunteer,who camefrom all walks of life.Around 20 percent were fromproblem backgrounds,some havinghad troubles with drugs or crime.It seemsthat there a lot more to education than university and books,and theChilean forests and a littleontactwith regular people may do a lot of a British prince.Unit 3:Basic listening practice:CABCDListening in:task 1:After thirteen years marriage,the woman wants to divorce herhusband claiming he is irresponsible When asked for the specific grounds for divorce,she gives these reasons:First,he keephanging jobs and the family has had to movefour times in thirteen years,but she wantstability for her children and herself Second,although he is paying the bills,they just live around the poverty line.Her children arebeing teased。
药物冷冻干燥技术的应用及其影响因素
从此，冻干技术迅速兴起!!!
冷冻干燥法的定义是什么？
• 冷冻干燥（freeze drying lyophilization）
是指先将湿物料冻结到其晶点温度以下，使 水分变成固态的冰，在低温减压条件下利用水的 升华性能，使物料低温脱水而达到干燥目的的一 种干燥方法。因为利用升华达到去水的目的，因 此又称为升华干燥（sublimation）。
冻结方 法和速 率
不同冻结方法产生不同 效果。预冻温度低， 冰核形成快，冰晶小， 比表面积大，聚集减 少。反之，较高预冻 温度下，较长的冻结 过程，冰晶生长变大， 容易聚集。
脂质体的性质
膜材组成 脂质体荷电性质 脂质体粒径
影响冻干制剂的因素
冻干品复水化 过程
冻干品复水化时，大量的水透过脂质双层，可 引起药物的渗漏。冻干脂质体复水化时，振动或 搅拌的强度、溶媒种类等也可影响水化脂质体的 粒径及药物保留率通过优化复水化条件可改善水 化脂质体的粒径和包封率。
冻干保护剂：表面活性剂类
聚乙烯吡咯酮
聚乙烯醇
PVPLeabharlann PVAPVP是一种多聚体,它对生物体或 生物大分子具有非特异性保护作
用;同时它也是一种非渗透性保 护剂,在细胞冻干保存中常与糖 类一起,主要通过与糖类间的氢 键作用和改变糖类的玻璃化温度
发挥作用,不同浓度和不同分子 量的PVP的作用不一样。
PVA是在冻干中常用的一种稳 定剂。它可以使纳米粒子的粒 径和多分散系数在冻干前后不 发生变化。PVA的分子碎片可 以与纳米粒子表面结合，且在 多次洗涤中也很难脱落，而这 些包裹在粒子表面的聚合物层 既可以稳定纳米粒，又可以提 高后者在冷冻过程中的稳定性 。
高一英语Unit The Million Pound Bank-Note试题
高一英语Unit The Million Pound Bank-Note试题1.【1】I find his lectures are very c__________, for he never sticks to the point.【答案】confusing【解析】句意：我发现他的课令人困惑不解，他总是跑题。
再结合首字母C和be动词后应该是形容词，confusing令人困惑不解，故填写confusing。
【2】Through careful __________(观察)he found the secret of the birds’ life.【答案】observation【解析】句意：通过仔细观察，他发现了鸟类生活的秘密。
再结合翻译， observation观察，故填写observation。
【3】Dr. Smith will d__________ a lecture on endangered species.【答案】deliver【解析】句意：史米斯博士将举办一个关于濒危物种的讲座。
再结合首字母d和will后应该是动词原形，deliver a lecture举办讲座，故填写 deliver。
【4】It’s very c_________of the manager to work at home in such bad weather.【答案】considerate【解析】句意：经理在这样恶劣的天气里在家里工作真是考虑周到。
形容词考虑周到的considerate，该词固定搭配be considerate of…对…考虑周到的。
故填considerate。
【5】Remember to stay calm in case of an e___________, or you’ll run into trouble.【答案】emergency【解析】句意：记得在紧急情况下保持镇静，否则你会遇到麻烦的。
2016Mini-lecture专业八级真题听力原文
about the strategies that people use to try and win arguments, and that makes arguing adversarial; it’s polarizing. And the only foreseeable outcomes are triumph—glorious triumph—or disgraceful defeat. (10) I think those are very destructive effects, and worst of all, it seems to prevent things like negotiation and collaboration. Um, I think the argument-as-war metaphor inhibits those other kinds of resolutions to argumentation. (11) And finally—this is really the worst thing—arguments don’t seem to get us anywhere; they’re dead ends. We don’t get anywhere.Oh, and one more thing. (12) That is, if argument is war, then there’s also an implicit aspect of meaning—learning with losing. And let me explain what I mean. (13) Suppose you and I have an argument. You believe a proposition, and I don’t. And I say, “Well, why do you believe that?” And you give me your reasons. And I object and say, “Well, what about…?” And you answer my objection. And I have a question: “Well, what do you mean? How does it apply over here?” And you answer myq uestion. Now, suppose at the end of the day, I’ve objected, I’ve questioned, I’ve raised all sorts of questions from an opposite perspective, and in every case you’ve responded to my satisfaction.And so at the end of the day, I say, “You know what? I guess you’re right.” Maybe finally I lost my argument, but isn’t it also a process of learning? So, you see arguments may also have positive effects. (14) So, how can we find new ways to achieve those positive effects? We need to think of new kinds of arguments. Here, I have some suggestions: If we want to think of new kinds of arguments, what we need to do is think of new kinds of arguers—people who argue. So try this: Think of all the roles that people play in arguments. There’s the proponent and the opponen t in an adversarial, dialectical argument. There’s the audience in rhetorical arguments. There’s the reasoner in arguments as proofs. All these different roles. Now, can you imagine an argument in which you are the arguer, but you’re also in the audience, watching yourself argue? (15) Can you imagine yourself watching yourself argue? That means you need to be supported by yourself. Even when you lose the argument, still, at the end of the argument, you could say, “Wow, that was a good argument!” Can you do that? I think you can. In this way, you’ve been supported by yourself.Up till now, I’ve lost a lot of arguments. It really takes practice to become a good arguer in the sense of being able to benefit from losing, but fortunately, I’ve had many, many colleagues who have been willing to step up and provide that practice for me.OK. To sum up, in today’s lecture, I’ve introduced three models of arguments. The first model is called the dialectical model, the second one is the model of arguments as proofs, and the last one is called the rhetorical model, the model of arguments as performances. I have also emphasized that though the adversarial type of arguments is quite common, we can still make arguments produce some positive effects. Next time, I will continue our discussion on the process of arguing.。
2010年英语专八听力mini-lecture原文+解析
本次真题的听力原文如下，注意文章中标粗的部分，是记笔记的重点部分：Paralinguistic features of languagesGood morning, everyone. Today we'll continue our discussion on describing language. Last week we examined such features of language as grammar, vocabulary, the sounds of language, etc. In this lecture, we'll look at another important aspect of language. Perhaps some of you may wonder what is this important aspect of language. Let me tell you. It refers to features of communication that takes place without the use of grammar and vocabulary. They are called ‘paralinguistic features of language'.These features fall into two broad categories: those that involve voice and those that involve the body.Now, the first category, is what we call vocal paralinguistic features. Vocal features are actually tones of voice. While they are, perhaps, not central to meaning in communication in the same way as grammar or vocabulary, they may, nevertheless, convey attitude or intention in some way. Let me give you some examples. The firstis whispering, which indicates the needs for secrecy. The second is breathiness. This is to show deep emotion. The third is huskiness, which is to show unimportants. The fourth is nasality. This is to indicate anxiety. The last is extra lip-rounding, which expresses greater intimacy, expecially with babies, for example. So we can see that there are a number of ways of altering our tone of voice. And when we do this consciously, we do it to create different effects in communication.Now, let's come to the second category, physical paralinguistic features, which involves the body. In addition to convey meanings with tone of voice, we can also express our intentions through the ways in which we use our bodies. You may ask: what are the ways, then? Let me sight some brief examples. The expression on our face, the gestures we make and even proximity or way we sit, are some of the ways we send powerful messages. About how we feel, or what we mean. Let me explain some of these in more detail. First, facial expression. Facial expression is a powerful conveyer of meaning. We all know smiling is an almost universal signal of pleasure or welcome. But there are other facial expressions that may not be so common. For instance, raising eye-brows - suggest that you are surprised or interested in something. Other facial actions, such as biting your lip, which indicates that you are deep in thinking, or are uncertain about something; compressing the lips, which show that you are making decisions; and avisible clenching of the teeth, to show that you are angry, are all powerful conveyers of meaning, too. The second in this category is gesture. You see, we use gesture to indicate a wide range of meanings. Though I have to emphasize that the actual gestures we use may be specific to particular cultures. That is to say different cultures have their own favorite gestures in conveying meaning. Here, a few examples may show you how powerful gestures can be. In British English behavior, shrugging shoulders may indicate an attitude of ‘I don't care', or ‘I don't know'. Crossing your arms may indicate relaxation. But it can also powerfully show you are bored. Waving can mean welcome and farewell.While scratching your head may indicate that you are at a loss. In othercultures, placing your hand upon your heart is to indicate that you are telling the truth. Pointing your finger at your nose means it's a secret. That's why we saythat gestures are culture bound. The third is proximity, posture andechoing. Proximity refers to the physical distance between speakers. This can indicate a number of things and can also be used to consciously send messages about intent. Closeness, for example, indicates intimacy or threat to many speakers.But distance may show formality, or lack of interest. Once again, I'd like tosay, proximity is also both a matter of personal style, and is often culture bound. So, what may seem normal to a speaker from one culture may appear unnecessarily close or distant to a speaker from another. And standing close to someone may be quite appropriate in some situations such as an informal party, but completely out of place in other situations, such as a meeting with a superior. Next, posture. Posture means the way in which someone holds his or her body, especially the back, shoulders and head, when standing, walking or sitting. A few examples. Hunched shoulders and a hanging head give a powerful indication of whether the person is happy or not. A lowered head when speaking to a superior, with or without eye contact can convey the appropriate relationship in some cultures. On the other hand, direct level eye contact, changes the nature of interaction, and can been seen as either open or challenging. Last, echoing. Now, what is echoing? Let me start with an example. Some of you may have noticed this phenomenon in your experience. When two people are keen to agree each other, they would likely, though unconsciously adopt the same posture, as if an imitation of each other. They sit or stand in the same manor. When used in this way, echoing appears to complement the verbalcommunication. Of course, when such imitation is carried out consciously, it often indicates that someone is marking at another speaker.Ok, in today's lecture, we looked at some paralinguistic features, such as tone of voice, gesture and posture. These features, together with linguistic features of language, like grammar, or vocabulary, are all part of the way we communicate with each other in face to face encounters. In our next lecture, we'll watch some video material, and see how people actually use paralinguistic means in communication to express their intention or desire or mood.整理一下，整篇文章的要点非常清晰：I. Vocal Paralinguistic Features1. whispering- the needs for secrecy2. breathiness- deep emotion3. huskiness- unimportants4. nasality- anxiety5. extra lip-rounding- greater intimacyII. physical paralinguistic features1. facial expression- powerful conveyer of meaning.--e.g.1 smiling: pleasure or welcome--e.g.2 raising eye-brows: surprised or interested in something--e.g.3 biting your lip:deep in thinking/ uncertain about something--e.g.4 compressing the lips: making decis ions--e.g.5 clenching of the teeth: angry2. gesture- culture bound--e.g.1 shrugging shoulders: 'I don't care', or 'I don't know'--e.g.2 crossing your arms: relaxation/ bored--e.g.3 waving: welcome and farewell--e.g.4 scratching your head: at a loss--e.g.5 placing your hand upon your heart: telling the truth--e.g.6 pointing your finger at your nose: it's a secret3. proximity, posture and echoing1). proximity: personal style & culture bound--e.g.1 closeness: intimacy, threat--e.g.2 distance: fomality, lack of interest2). posture: the way in which someone holds his or her body--e.g.1 Hunched shoulders and a hanging head: happy or not--e.g.2 A lowered head, eye contact: the appropriate relationship--e.g.3 direct level eye contact: open or challenging3). echoing: to complement the verbal communication运用各种自己熟悉的笔记符号，将上述列表中的内容快速记下来，只可以更少，不能更多。
新理念外语网络教学平台第二版综合B2U7A
崭新版第二版综合B2U7-APartIListeningComprehension(10minutes)SectionADirections:Inthissection,youwillheartenstatements.Numbers1to6arebasedonTextAwhilethere starebasedonTextB.EachstatementwillbereadONLYONCE.Listencarefullyanddecidewhethereachstate mentistrueorfalse.1.TFScript:Englishhasrichervocabularythanothermajorlanguagesbecauseitborrowsalotofwordsf romotherlanguages.正确答案：A2.TFScript:Anglo-SaxonEnglish,asthecoreofourlanguage,isusuallycomplexanddirect.正确答案：B3.TFScript:Itisbelievedthatmanymodernlanguagesmayderivefromacommonparentlanguage.正确答案：B4.TFScript:FrenchhasagreatinfluenceonEnglishlanguageforitwastheonlylangu ageusedin1066.正确答案：A5.TFScript:WilliamCaxtonstartedthecommunicationsrevolutioninEnglandandgreatlyenrichedEng lishwiththenewthoughtsofEuropeanRenaissance.正确答案：A6.TFScript:ThermometerisaborrowedwordfromLatin.正确答案：B7.TFScript:Englishisagloballanguageintermsofthenumberofusers,thedepthofpenetrationandthe rangeoffunctions.正确答案：A8.TFScript:Itisestimatedthataboutaquarteroftheworld'spopulationcanspeaksomeEnglish.正确答案：B9.TFScript:AccordingtotheTextB,therewillbeanewlanguagerulingtheworldinahundredyears.正确答案：B10.A)TFScript:Languageshiftsareslowanddifficulttopredict.正确答案：ASectionBDirections:Inthissection,youwillhearapassagethreetimes.Whenthepassageisreadforthefirst time,youshouldlistencarefullyforitsgeneralidea.Whenthepassageisreadforthesecondtime,youare requiredtofillintheblankswiththeexactwordsyouhavejustheard.Finally,whenthepassageisreadfor thethirdtime,youshouldcheckwhatyouhavewritten.En glishisworldfamouslanguage usedmost(11)_________________as a secondlanguage and(12)_________________languageinmanypartsoftheworld.The mainreasonforthisvast(13)_________________ ofEnglishlanguageisattributedtotheBritish(14)_________________overmajorpartsoftheworld.AfterWorldWarII,UnitesStateshasreceiveda kickstartin(15)_________________andculturalareaswhichalso(16)_________________highlytothew idespread(17)_________________ofEnglishasanofficiallanguage.The(18)_________________statis ticsshowthatoverabillionpeoplespeakEnglishallovertheworld.Thisisbecauseofthedirectrelation of(19)_________________invariousareas.KnowingEnglishisconsideredasamajorfactorthatcan(20)_ ________________one'ssuccessinhisprofessionalarena.Script:Englishisaworldfamouslanguageuse dmostcommonlyasasecondlanguageandofficiallanguageinmanypartsoftheworld.Themainreasonforthi svastusageofEnglishlanguageisattributedtotheBritishattackovermajorpartsoftheworld.AfterWor ldWarII,UnitesStateshasreceivedakickstartineconomicalandculturalareaswhichalsocontributedh ighlytothewidespreadacceptanceofEnglishasanofficiallanguage.Thecurrentstatisticsshowthatov erabillionpeoplespeakEnglishallovertheworld.Thisisbecauseofthedirectrelationoflanguageande xcellenceinvariousareas.KnowingEnglishisconsideredasamajorfactorthatcaninterferewithone'ss uccessinhisprofessionalarena.正确答案：commonly正确答案：official正确答案：usage正确答案：attack正确答案：economical正确答案：contributed正确答案：acceptance正确答案：current正确答案：languageandexcellence正确答案：interferewithPartIIReadingComprehension(25minutes)SectionADirections:Inthissection,thereisapassagewithseveralblanks.Youarerequiredtoselectonewor dforeachblankfromalistofchoicesgiveninawordbankfollowingthepassage.Readthepassagethroughca refullybeforemakingyourchoices.Eachchoiceinthebankisidentifiedbyaletter.Youmaynotuseanyoft hewordsinthebankmorethanonce.Thetoleranceforchangealsorepresentsdeeplyrootedideasoffreedom.DanishscholarOttoJespers enwrotein1905,"TheEnglishlanguagewouldnothavebeenwhatitisiftheEnglishhadnotbeenforcenturie sgreatrespectersofthe21ofeachindividualandifeverybodyhadnotbeenfreeto22newpathsforhimself."Ilikethatidea.Considerthatthesamecultural23prod ucingt he Englishlanguagealso24thegreatprinciplesoffreedomandrightsofmaninth e25world.Thefirstshoots26inEngland,andtheygrewstrongerinAmerica.TheEnglish-speakingpeopleshavedefeatedalleffortstobuild27aroundtheirlanguage.Indeed,theEnglishlanguageisnotthespecial28ofgrammarians,languagepolice,teacher s,writersortheintellectual29.Englishis,andalwayshasbeen,the30ofcommonman.A)soilB)conservationC)nourishedD)preserveE)workoutF)sprangupG)eliteH)makeforI)tongueJ)powerK)fencesL)libertiesmodernN)strikeoutO)mouth21.______________________正确答案：L22.______________________正确答案：N23.______________________正确答案：A24.______________________正确答案：C25.______________________正确答案：M26.______________________正确答案：F27.______________________正确答案：K28.______________________正确答案：D29.______________________正确答案：G30.______________________正确答案：ISectionBDirections:Thereareseveralpassagesinthissection.Eachpassageisfollowedbysomeque stionsorunfinishedstatements.ForeachofthemtherearefourchoicesmarkedA),B),C)andD).Youshould decideonthebestchoice.PassageOneQuestions31to35arebasedonthefollowingpassage.A)Whenaconsumerfindsthatanitemsheorheboughtisfaultyorinsomeotherwaydoesnotliveuptothemanufacturer'sclaim,thefirststepistopresentthewarranty(保单),oranyotherrecordswhichmighthelp,atthestoreofpurchase.Inmostcases,thisactionwillproduceresults.However,ifitdoesnot,therearevariousmeanstheconsumermayusetogainsatisfaction.Asimpleandcommonmethodusedbymanyconsumersistocomplaindirectlytothestoremanager.Ingeneral,the"higherup"theconsumertakeshisorhercomplaint,thefasterheorshecanexpectittobesettled.Insuchacase,itisusuallysettledintheconsumer'sfavor,assumingheorshehasajustclaim.Consumersshouldcomplaininpersonwheneverpossible,butiftheycannotgettotheplaceofpurchase,itisaccepplainingisusuallymosteffectivewhenitisdonepolitelybutfirmly,andespeciallywhentheconsumercandemonstratewhatiswrongwiththeiteminquestion.Ifthiscannotbedone,theconsumerwillsucceedbestbypresentingspecificinformationastowhatiswrong,ratherthanbymakinggeneralstatements.Forexample,"Theleftspeakerdoesnotworkatallandthesoundcomingoutoftherightoneisunclear"isbetterthan"Thisstereodoesnotwork."Thestoremanagermayadvisetheconsumertowritetothemanufacturer.Ifso,theconsumershoulddothis,statingthecomplaintaspolitelyandasfirmlyaspossible.Butifapolitecomplaintdoesnotachievethedesiredresult,theconsumercangoastepfurther.Sheorhecanthreatentotakethesellertocourtorreportthesellertoaprivateorpublicorganizationresponsibleforprotectingconsumers'rights.31.Whenaconsumerfindsthathisorherinit,thefirstthingheorsheshoulddoisto____.complainpersonallytothemanagerthreatentotakethesellertocourtwriteafirmletterofcomplainttothestoreofpurchaseshowsomewrittenproofofthepurchasetothes tore正确答案：D32.Howcanaconsumermakehisorhercomplaintmoreeffective,accordingtothepassage?Explainexactly whatiswrongwiththeitem.Threatentotakethesellertocourt.Makepoliteandgeneralstatementsaboutt heproblem.Avoidhavingdirectcontactwiththestoremanager.正确答案：A33.Accordingtothepassage,whichofthefollowingissuggestedasthelastalternativethatconsumersm ayturnto?plaintothemanufacturer.Writeacomplaintletter tothemanager.TurntotheConsumers’RightsProtectionOrganizationforhelp.正确答案：D34.Thephrase"liveupto"(inPara.1)inthiscontextmeans____.meetingthestandardofrealizingthepu rposeoffulfillingthedemandsofkeepingthepromiseof正确答案：A35.Thepassagetellsus____.howtosettleaconsumer’scomplaintaboutafaultyitemhowtomakeaneffec tivecomplaintaboutafaultyitemhowtoavoidbuyingafaultyitemhowtodealwithcomplaintsfromcustome rs正确答案：BPassageTwoQuestions36to40arebasedonthefollowingpassage.IfyouaskpeopletonameonepersonwhohadthegreatesteffectontheEnglishlanguage,youwillgetans werslike"Shakespeare","SamuelJohnson"and"Webster"butnoneofthesemenhadanyeffectatallcompare dwithamanwhodidn'tevenspeakEnglish—WilliamtheConqueror.Before1066,inthelandwenowcallGreatBritainlivedpeoplebelongingtotwomajo rlanguagegroups.Inthewest-centralregionlivedtheWelsh,whospokeaCelticlanguage,andinnorthlivedtheScots,whoselanguage,t houghnotthesameasWelsh,wasalsoCeltic.IntherestofthecountrylivedtheSaxons,actuallyamixtureo fAnglos-Saxons,andotherGermanicandNordicpeoples,whospokewhatwecallAnglo-Saxon(orOldEnglish),aGermanicLanguage.Ifthisstateofaffairshadlasted,Englishtodaywouldbeclo setoGerman.Butthisstateofaffairsdidnotlast.In1066theNormansledbyWilliamdefeatedtheSaxonsan dbegantheirruleoverEngland.Foraboutacentury,FrenchbecametheofficiallanguageofEnglandwhileO ldEnglishbecamethelanguageofpeasants.Asaresult,EnglishwordsofpoliticsandthelawcomefromFren chratherthanGerman.Insomecases,modernEnglishevenshowsadistinctionbetweenupper-classFrenchandlower-classAnglo-Saxoninitswords.Weevenhavedifferentwordsforsomefoods,meatinparticular,dependingonwhetherit isstilloutinfieldsorathomereadytobecooked,whichshowsthefactthattheSaxonpeasantsweredoingth efarming,whiletheupper-classNormansweredoingmostoftheeating.WhenAmericansvisitEuropeforthefirsttime,theyusuallyfi ndGermanymore"foreign"thanFrancebecausetheGermantheyseeonsignsandadvertisementsseemsmuchmo redifferentfromEnglishthanFrenchdoes.FewrealizethattheEnglishlanguageisactuallyGermanicini tsbeginningandthattheFrenchinfluencesarealltheresultofoneman'sambition.36.Accordingtothepassage,___________hadthegreateffectontheEnglishlanguage.ShakespeareSamu elJohnsonWebsterWilliamtheConqueror正确答案：D37.ThetwomajorlanguagesspokeninwhatisnowcalledGreatBritainbefore1066were__ ___.WelshandScottishNordicandGermanicCelticandOldEnglishAnglo-SaxonandGermanic正确答案：C38.Whichofthefollowinggroupsofwordsare,byinference,rootedinFrench?President,lawyer,beef.P resident,bread,water.Bread,field,sheep.Folk,field,cow.正确答案：A39.WhydoesFranceappearlessforeignthanGermanytoAmericansontheirfirstvisittoEurope?Becausem ostadvertisementsinFranceappearinEnglish.BecausetheyknowlittleofthehistoryoftheEnglishlang uage.BecausemanyFrenchwordsaresimilartoEnglishones.BecausetheyknowFrenchbetterthanGerman.正确答案：C40.Whatisthesubjectdiscussedinthetext?ThehistoryofGreatBritain.Thesimi larityofGreatBritain.TheruleofEnglandbyWilliamtheConqueror.TheFrenchinfluencesontheEnglishlanguage.正确答案：DPartIIIVocabularyandStructure(10minutes)Directions:Thereareanumberofin completesentencesinthispart.ForeachsentencetherearefourchoicesmarkedA),B),C)andD).ChoosetheONEthatbestcompletesthesentence.41.Beforethe arrivalofthe whiteman,Australiawas________solelybyaborigines.inhabitedshelteredlivedinhabiting正确答案：A42.Shewasalwaysonthe________forsomenewcalamity.attentionalertconsciousnessalter正确答案：B43.YanFu's_______onthetranslationcircleisimmeasurable.influenceaffectconsequenceresult正确答案：A44.Thecountry________fromabackwardagriculturalcountryintoanadvancedindustrialcountry.tran smissiontransformedtransferredtransported正确答案：B45.Thenew_______ofthecountrywerefixedafterthewar.A)capitalslandsfrontiersboundaries正确答案：D46.Literatureandarthaveagreat_______people'sideology.impactoninfluenceoneffectonimpressio non正确答案：B47.Sally_______allfoolishcommentsandkeptonworking.excludeddischargedignoreddenied正确答案：C48.Let'shavemore_____andlessfightinginthehouse.welfareaffectionharmonydiscussion正确答案：C49.Theclothesapersonwearsmayexpresshis_____orsocialposition.curiositystatusdeterminations ignificance正确答案：B50.Atthefirstthoughttheyoungmanwantedtoargue,butthenextmomenthehadhimself_____.beyondcontroloutofcontrolincontrolatcontrol正确答案：C51.Thenewcomer_____himselfinthelargeleatherchair.satkeptinstalledsank正确答案：C52.ThismorningI__________thewashingwhenitstartedtorain,soIhadtobringitallinagain.wasjustt ohangoutwasjusthangingouthadjusthangedouthavejusthangedout正确答案：B53.Theywereshipwreckedonatinyisland_________.offthecoastofbelongingtoJapanoffofthecoastof JapanoffthecoastbelongstoJapanoffthecoastofJapanA)正确答案：D54.Itwasatimeoftrouble:moneywasshort,andfriends_________away.drencheddrifteddrilledpull正确答案：B55.Thepolicechief,whofearsthatthecasecouldbecomeanationalincident,isopposed___________ita nypublicity.togivetogivingtobegivingtohavegiven正确答案：B56.Ishouldsayheisnot_________ascholarasawriter.toomuchverymuchsomuchasmuch正确答案：C57.Hemighthavebeendead_________thearrivalofthedoctors.butforexceptforwithon正确答案：A58.________Iadmirehimasadoctor,Idon'tlikehimasaman.MuchasSomuchAsmuchMuchso正确答案：A59.A)Theparent'sgroupcalledforatotal____________onviolentvideogames.banbaradditionaffection正确答案：A60.The____________ofJapanbroughtWorldWarIItoaclose.resistancesurrenderdisadvantageopponen t正确答案：BPartIVTranslation(10minutes)Directions:CompletethesentencesbytranslatingintoEnglishtheChi nesegiveninbrackets.Readingthecommentsinthemargins,____________________我(不由自主地想)thatthepreviousreadermustbeasentimentalist.正确答案：Icouldn'thelpthinkingStudentsfromcountrieswithadrasticallydifferentcultureandlanguagef romtheU.S.haveto____________________(经受大批的文化冲击)whentheyfirstarrive.正确答案：absorbagreatdealofculturalshockFailingtoarriveontimeorwithoutfullpreparationforajobintervi ew____________________你(将处于不利地位).正确答案：you'llbeatadisadvantageThoughshefounditdifficultandboringmajoringinmathshe____________ ________咬(紧牙关)andgotonwithit.65.正确答案：grittedherteethThattoleranceforchangealso____________________体(现了根深蒂固的自由精神).正确答案：representsdeeply-rootedideasoffreedom。
Presentation Anti Corruption Compliance 130514
5
Public Officials Public Officials means :
anyone who performs public functions in a legislative, judicial or administrative capacity; anyone acting in an official capacity for or on behalf of
Unit 10 courseware for the second semester of seve
Course arrangement and time planning
Course Arrangement
This unit consistency of a series of lectures, discussions, and activities designed to engage students in critical thinking and hands-on learning experiences The course material will cover a range of topics related to environmental protection and sustainability, including climate change, pollution, biodiversity conservation, and sustainable development
Summarizing and paraphrasing
Guide students in summarizing the main ideas and key points of the text in their own words, as well as paraphrasing specific details or examples to demonstrate their understanding
Guide and demonstration of reading skills
Skimming and scanning techniques
Teach students how to quickly skim through a text to identify the main idea and key points, as well as how to scan for specific information or details
大学的特殊课程英语作文
The Unique Courses at My UniversityIn the vibrant and diverse academic environment of my university, a range of exceptional courses stand out, offering students unique opportunities to explore their interests and develop their skills. One such course is the "Interdisciplinary Innovations" seminar, which combines the best of several disciplines to foster creativity and problem-solving.Led by a team of experts from diverse backgrounds, the seminar introduces students to a range of perspectives and methodologies. Each session begins with a topic proposed by the students, allowing them to pursue their own passions and curiosity. Whether it's exploring the intersection of art and science, analyzing social media trends, or developing sustainable solutions to environmental challenges, the course encourages students to think outside the box.Another noteworthy course is the "Global Perspectives on Local Issues" program, which offers students the chance to immerse themselves in different cultures and understand the global implications of local decisions. Through acombination of lectures, case studies, and field trips, the program brings to life the interconnectedness of the world and the importance of considering global perspectives in addressing local problems.For students interested in entrepreneurship, the "Startup Lab" provides a hands-on experience in launching and growing a business. The course covers everything from idea generation and market research to pitching and funding. Participants are paired with mentors from the local startup community, who provide guidance and insights into the world of entrepreneurship.These are just a few examples of the unique courses offered at my university. Each course is designed to challenge students,刺激他们的批判性思考和创新精神，同时培养他们的跨学科合作和领导能力。
年级英语试卷听力部分【含答案】
年级英语试卷听力部分【含答案】专业课原理概述部分一、选择题（每题1分，共5分）1. 在英语听力中，哪个词通常用来表示“请听录音”？A) ListenB) HearC) WatchD) Look2. 以下哪个词组表示“听力练习”？A) Listening practiceB) Speaking practiceC) Reading practiceD) Writing practice3. 英语听力材料中，哪个词通常用来表示“问题”？A) QuestionB) AnswerC) TopicD) Idea4. 在英语听力中，哪个词通常用来表示“对话”？A) DialogueB) MonologueC) EssayD) Story5. 以下哪个词组表示“听写练习”？A) Listening prehensionB) Dictation practiceC) Grammar practiceD) Vocabulary practice二、判断题（每题1分，共5分）1. 英语听力中的独白是指一个人说话，没有其他人回应。
（√/×）2. 英语听力中的对话通常涉及两个或多个人之间的交流。
（√/×）3. 英语听力中的新闻报道通常包含详细的事件描述和背景信息。
（√/×）4. 英语听力中的讲座通常由专家或学者进行，涉及特定主题的深入讲解。
（√/×）5. 英语听力中的广告通常旨在推销产品或服务，语言风格较为夸张。
（√/×）三、填空题（每题1分，共5分）1. 英语听力中的______是指一个人说话，没有其他人回应。
2. 英语听力中的______通常涉及两个或多个人之间的交流。
3. 英语听力中的______报道通常包含详细的事件描述和背景信息。
4. 英语听力中的______通常由专家或学者进行，涉及特定主题的深入讲解。
5. 英语听力中的______通常旨在推销产品或服务，语言风格较为夸张。
2024年Complete version of English natural phonics P
11
Word spelling skills
01
02
03
04
Understanding telephone symbols and their
corresponding sounds
2024/2/28
Learning to blend sounds together to form words
Practicing spelling words by sounding out each letter
• Applications: NPP can be applied to all levels of English language learning, from beginner to advanced It can be used in both classroom and individual learning settings, and can be integrated into a wide range of current materials and teaching approaches
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Common promotion patterns of letter combinations
• Certain letter combinations of many have predictable promotion patterns in English
新理念英语上机测试华工版BUA
全新版第二版听说B4U9-APart I Listening Comprehension ( 29 minutes )Section ADirections: In this section, you will hear several conversations. At the end of each conversation, one or more questions will be asked about what was said. Both the conversations and the questions will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices marked A), B), C) and D), and decide which is the best answer.1.A) One month.B) Two months.C) Three times.D) Four times.Script: Woman: How long can I hang on the books that I borrow?Man: The borrowing period is one month, but of course books can be renewed. You can renew any item a maximum of three times. Question: How many times can the student renew her borrowed books?正确答案： C2.A) 75 pounds.B) 150 pounds.C) 75 dollars.D) 150 dollars.Script: Woman: I’d like to attend the computing conference on Saturday and Sunday only. Can you tell me how much it will cost?Man: It’s 75 pounds for each day.Question: How much should the woman pay for attending the conference?正确答案： B3.A) Husband and wife.B) Co-workers.C) Professor and student.D) Father and daughter.Script: Woman: I think I have got the flu. There are about 6 people off at the moment with flu in the company.Man: Yeah, it is going round. It is best if you stay at home for a day or two I should think. I will take care of the office.Question: What may be the relationship between the two speakers?正确答案： B4.A) 326211.B) 326311.C) 336211.D) 336122.Script: Man: Is that 326211? Could I speak to Potter, please?Woman: I’m afraid you have got a wrong number. It is 336211 here.Question: What is the number that the man dialed?正确答案： C5.A) He wants to change his surgery.B) He wants to see the doctor.C) He wants to change his medicine.D) He wants to change the date of his medical check.Script: Woman: Mark Price’s Surgery. Can I help you?Man: Yes, please. I would like to change my appointment of medical check with the doctor to March 15, please.Question: What does the man call for?正确答案： DQuestions 6 to 8 are based on the conversation you have just heard.Script: Woman: Oh sorry, what was I saying? I lost my train of thought.Man: You were telling me about the book you’re reading. Woman: Oh, yeah. I must have had one of those senior moments of forgetting things.Man: Welcome to the club. That’s what happens when you’re over-the-hill like we are.Woman: We’re not over-the-hill! You may be an old man, but I still like to think of myself as middle-aged. Isn’t 70 the new 60?Man: That’s what they say, but I don’t mind aging. I may be a little absent- minded now and then, but I’m not weak. What I can’t stand is being treated like I am. The other day, I sat at a table at a restaurant for 20 minutes while the waitress ignored me. She waited on all of the tables around me first, and when she finally came to take my order, she didn’t even apologize.Woman: Ageism is everywhere. What I hate is to be talked to like I’m a child. Some people think that if you’ve got gray hair, you’re not all there. I’m as sharp as ever.Man: I know, but do you know what we’re doing?Woman: What?Man: We’re complaining. That’s what old people are supposed to do all the time, right?Woman: You’ve got a point there. Let’s go do something more productive before anyone notices!6.A) A travelling experience.B) A movie.C) A book.D) A piece of music.Script: What was the woman telling the man before she lost the track of thought?正确答案： C7.A) He cannot bear the way people treated him.B) He did mind getting old.C) He thought he was weak.D) He thought he was not absent-minded at all.Script: What is the man’s feeling towards his old age?正确答案： A8.A) She hates to wait in a restaurant.B) She hates to be talked to like she is a child.C) She hates to be called grandma by strangers.D) She hates not being treated with admiration.Script: What does the woman hate about being old?正确答案： BQuestions 9 to 11 are based on the conversation you have just heard.Script: Woman: Today is July 15th, I’m almost ready for my granddaughter’s visit. She’ll be here tomorrow and I want everything to be perfect.Man: What have you planned?Woman: I’m going to spoil her. My daughter is very strict and doesn’t allow her to do anything that a normal 10-year-old wants to do.Man: Like what?Woman: Well, her time is very structured and strictly controll ed. She’s never been allowed any time for just fun.Man: And you’re taking off the restrictions.Woman: That’s right. She can play as much as she wants to for the next week. I don’t want her to miss out on any experiences just because her mother is overprotective. There will be no curfews and no time schedules.Man: Are you sure that’s a good idea? I’m sure your daughter has instructions about how your granddaughter should behave and the punishments she should get if she misbehaves. Woman: Y ou’re right about that. I’m expecting a long list of rules for my granddaughter while she’s here, but she shouldn’t expect me to toe the line. I’m the grandmother after all, so I have special privileges. Nobody tells me what to do with my own granddaughter.Man: How did a free spirit like you end up with a daughter who is so strict with rules?Woman: Beats me.Man: She’s not going to thank you for spoiling her daughter, you know.Woman: I know, but I’m her mother and there’s still a thing or two I can teach her about raising a daughter!9.A) July 15th.B) July 16th.C) July 17th.D) July 18th.Script: When will the granddaughter visit？正确答案： B10.A) Free.B) Structured and controlled.C) Full of fun.D) Without any control.Script: What is the granddaughter’s daily schedule like?正确答案： B11.A) She will be very strict with her.B) She will let the girl play as much as she wants.C) She will follow her daughter’s list of rules.D) She will make a tight schedule for the girl.Script: What would the grandma do with the granddaughter?正确答案： BSection BDirestions：Listen to three short passages. At the end of each passage, you will hear some questions. All the recordings will be played once only. After you hear a question, please choose the best answer from the four choices marked A), B), C) and D).Passage OneQuestions 12 to 14 are based on the passage you have just heard.Script: Mm, blueberries. It’s the height of the season, and I’ve been tossing a handful into cereal, into pancakes or just straight into my mouth. This is a so-called SUPER fruit that may hold you back from aging and are considered extremely good to your eyes. Many of our crops were cultivated thousands of years ago, and we don’t know the individuals responsible. Not so for blueberries. Because the blueberry wasn’t planted by h uman beings until just about a century ago. And we have a botanist named Fred Coville to thank.In 1912 if you wanted blueberries, you picked the wild variety. And it was devilishly difficult to get the plants to grow anywhere but where they were naturally found. Coville figured out after many dead ends that blueberries need exceedingly acidic soil: most plants like the soil at a neutral pH of about 7. Blueberries do best when the pH is about 4.5.Colville also determined that blueberries can’t self-fertilize, so the grower must make sure the crop can be cross-pollinated. His research efforts are described in an article in the U.S. Department of Agriculture magazine Agricultural Research. So next time you pop a blueberry, don’t forget to thank Fred.12.A) Not known.B) Thousands of years ago.C) A decade ago.D) A century ago.Script: When was the blueberry first planted by mankind?正确答案： D13.A) Wild land.B) Soil at a pH of about 7.C) Soil at a pH of about 4.5.D) Soil at a pH of about 8.5.Script: What kind of soil will you possibly find blueberries be planted?正确答案： C14.A) Anti-virus.B) Antibiotic.C) Good to your eyes.D) Good to your skin.Script: What is the assumed function of blueberries?正确答案： CPassage TwoQuestions 15 to 17 are based on the passage you have just heard.Script: My formula for staying young is simple: concentrate on the part of you that’s young and growing your brain. Keep your mind awake and you’ll stay young all over. These are exciting times. Take an interest in the world around you, and make a point of learning at least one new thing every day.Regardless of your age, it’s not too late to make your life more interesting. I know a housewife with no previous knowledge who made herself into an outstanding industrial designer. I know a retired electrical engineer who has become a highly paid ceramic artist.Get over the notion that you are ever too old to go back to school. I know a man who entered medical college at 70. He got his doctor’s degree with honors and became an eminent physician. Another man went to law school at 71, and is now an active lawyer.In spite of years, staying young is easy for those who live in the future. You can do it if you care enough to try. Keep your mind awake and active; that’s o nly youth elixir guaranteed to work.15.A) Have good supplement diet.B) Find some friends.C) Keep the mind young.D) Go travelling.Script: What is the speaker’s suggestion for staying young?正确答案： C16.A) She made herself an outstanding designer.B) She became an electrical engineer.C) She became a paid ceramic artist.D) She became a teacher.Script: What does a housewife do in her old age?正确答案： A17.A) A bachelor’s degree in medicine.B) A master’s degree in medicine.C) A doctor’s degree in medicine.D) A postgraduate in medicine.Script: What degree does the 70-year-old man get?正确答案： CPassage ThreeQuestions 18 to 20 are based on the passage you have just heard.Script: Senior citizen is a common polite designation for an elderly person in both UK and US English, and it implies or means that the person is retired. This in turn implies or in fact means that the person is over the retirement age, which varies according to country. Synonyms include pensioner in UK English and retiree and senior in US English. Some dictionaries describe widespread usage of "senior citizen" for people over the age of 65. "Senior citizen" is replacing the term old-age pensioner traditionally used in UK English.When defined in an official context, "senior citizen"is often used for legal or policy-related reasons in determining who is eligible for certain benefits available to the age group. It is used in general usage instead of traditional terms such as "old person", "old-age pensioner", or "elderly" as a courtesy and to signify continuing relevance of and respect for this population group as "citizens" of society, of "senior" rank.The term was apparently coined in 1938 during a political campaign. It has come into widespread use in recent decades in legislation, commerce, and common speech. Especially in less formal contexts, it is often abbreviated as "senior(s)", which is also used as an adjective. In commerce,businesses often offer "senior discounts", sometimes with a special "senior discount card".18.A) People between 55 to 65.B) People above 60.C) People older than 70.D) People over the age of 65.Script: Which age group does the term of "senior citizens" refer to?正确答案： D19.A) It is used for politeness.B) It is used for legal or policy-related reasons.C) It is used to show respect.D) It is a traditional use.Script: What is "senior citizen" defined in an official context?正确答案： B20.A) In 1838.B) In 1998.C) In 1938.D) In 1948.Script: When was the term first made?正确答案： CSection CDirections: In this section, you will hear a passage three times. When the passage is read for the first time, you should listen carefully for its general idea. When the passage is read for the second time, you are required to fill in the blanks with the exact words you have just heard. Finally, when the passage is read for the third time, you should check what you have written.Aging is the process of growing old. It occurs eventually in every living thing provided, of course, that an illness or accident does not kill it prematurely. The most (21)_________________ outward signs of aging may be seen in old people, such as the graying of the hair and the wrinkling of the skin. Signs of aging in a pet dog or cat include loss of energy, a decline in (22)_________________ and eyesight, or even a slight graying of the coat. Plants age too, but the signs are much harder to (23)_________________ .Most body parts grow bigger and stronger, and function more effectively during childhood. They reach their peak at the time of maturity, or early (24)_________________ . After that, they begin to decline. Bones, for example,gradually become lighter and more brittle. In the aged, the joints between the bones also become rigid and more(25)_________________ . This can make moving very painful. All the major organs of the body show signs of aging. The brain, for example, works less efficiently, and even gets smaller in size. Thinking process of all sorts are slowed down. Old people often have trouble in (26)_________________ the recent events. One of the most serious changes of old age (27)_________________ in the arteries, the blood vessels that lead from the heart. They become thickened and constricted, allowing less blood to flow to the rest of the body. This condition (28)_________________ , directly or indirectly, for many of the diseases of the aged. It may, for example, result in heart attacks.Aging is not a (29)_________________ process. Different parts of the body wear out at different rates. There are great differences among people in their rate of aging. Even the cells of the body differ in the way they age. The majority of cells are (30)_________________ of reproducing themselves many times during the course of a lifetime. Nerve cells and muscle fibers can never be replaced once they wear out.Script: Aging is the process of growing old. It occurs eventually in every living thing provided, of course,that an illness or accident does not kill it prematurely. The most familiar outward signs of aging may be seen in old people, such as the graying of the hair and the wrinkling of the skin. Signs of aging in a pet dog or cat include loss of energy, a decline in hearing and eyesight, or even a slight graying of the coat. Plants age too, but the signs are much harder to detect.Most body parts grow bigger and stronger, and function more effectively during childhood. They reach their peak at the time of maturity, or early adulthood. After that, they begin to decline. Bones, for example, gradually become lighter and more brittle. In the aged, the joints between the bones also become rigid and more inflexible. This can make moving very painful.All the major organs of the body show signs of aging. The brain, for example, works less efficiently, and even gets smaller in size. Thinking process of all sorts are slowed down. Old people often have trouble in remembering the recent events. One of the most serious changes of old age occurs in the arteries, the blood vessels that lead from the heart. They become thickened and constricted, allowing less blood to flow to the rest of the body. This condition accounts, directly orindirectly, for many of the diseases of the aged. It may, for example, result in heart attacks.Aging is not a uniform process. Different parts of the body wear out at different rates. There are great differences among people in their rate of aging. Even the cells of the body differ in the way they age. The majority of cells are capable of reproducing themselves many times during the course of a lifetime. Nerve cells and muscle fibers can never be replaced once they wear out.正确答案： familiar正确答案： hearing正确答案： detect正确答案： adulthood正确答案： inflexible正确答案： remembering正确答案： occurs正确答案： accounts正确答案： uniform正确答案： capablePart II Oral Tasks ( 2 minutes )Section AInterpret the following Chinese passage into English. You can either interpret it sentence by sentence or give out themain points in your own words. You will have two minutes for preparation and three minutes for interpretation.31. 科学家们相信衰老（aging）的过程是由人体内在的生物钟控制的。
第十讲(解析版)2021年高二英语暑假精品课程(外研版)
2021年新高二暑假精品课程之预习+巩固+娴熟+突破第十讲（解析版）【学习目标】1．科学回顾梳理高一学年所学所接触的重点难点词汇和短语，句型和句式，借助语篇结构的语言环境夯实基础，熟练把控语篇脉络和词汇记忆，进而实现词汇量的飞跃，且有助于答题技巧的熟练形成。
2．借助宝贵的暑假时间，科学高效迎对新课，新知识，新语言现象，走近高考，从容应对和解决高中英语的基本技能，达到知识，能力和技巧的飞跃和突破。
【梳理重难点】Ⅰ.词汇初探1．artificial adj.人造的，人工的2．victim n．受害者3．capacity n．能力才能4．assistant n．助手，助理→assist v．帮助；协助→assistance n．援助；帮助5．potentially ad v.潜在地→potential adj.潜在的；可能的n．潜力；潜能6．analyse v．分析→analysis n．分析；解析7．illegal adj.非法的，违法的→legal adj.法定的；合法的8．immoral adj.不道德的，道德败坏的→moral adj.道德的；精神上的Ⅱ.短语互译1．按照；根据 according_to 2．出售 on_sale3．关心；挂念 be_concerned_about 4．有……的感觉；想要 feel_like5．与此相反；相比之下 in_contrast 6．挂出；闲逛 hang_out7．be based on 根据；_以……为基准 8．after all 毕竟；_究竟9．wipe out 消灭；彻底摧毁；擦掉 10．in the long run 从长远看来11．at risk 处境危险 12．lie in 在于。
1 artificial adj.人造的，人工的Those precious stones are artificial.那些宝石是人造的。
[归纳拓展](1)artificial intelligence人工智能artificial emotion假装的情感artificial rainfall人工降雨an artificial satellite人造卫星an artificial smile假笑(2)artificially ad v.人工地；人为地；不自然地[即时巩固]完成句子①The growers use both natural and_artificial_light.栽培者既用自然光也用人造光。
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Dept. of Physics and Materials Science City University of Hong Kong
References:
H.E. Davis, G.E. Troxell, in chapter 16 of “The Testing of Engineering Materials”, 1982. 2. J.S. Ceurter et al., “Advanced Materials Processes” (April 2002), p.29-31. 3. T. Adams, “Advanced Materials Processes” (April 2002), p.32-34.
Touch inspection using finger along the surface (2-3 cm/s.) Light reflection method No-parallex method
Penetrant test
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Penetrant test
Suitable for locating surface discontinuities, such as cracks, seams, laps, laminations in non-porous materials. Applicable to in-process, final, and maintenance inspection. ASTM E 165 General procedure:
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Advantage of Knowing the defects
• Defects are usually stress raiser • Stress raiser can cause premature failure Over design to overcome pre-mature failure Bulky/heavy design • Catastrophic/sudden/unpredicted failure loss of lives and money • Quality control • Better design
1. When a = 2 mm, max load = (2000 0.07927)/1.5 = 16.8 kN 2. When a = 1 mm, max load = (2000 0.05605)/1.5 = 23.6 kN 3. When a = 0.1 mm, max load = (2000 0.01772)/1.5 = 75.2 kN
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NDE methods for location of defects
Surface defects detection
Visual inspection Liquid penetrant test Magnetic particle method
Acoustic methods
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Visual inspection
It should never be omitted. Use low-power magnifying glass or microscopes (remember to take permanent photographic record) Surface roughness:
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Better design (example)
Consider a rectangular bar 10mm x 5 mm which will be used to support some load. The steel chosen had yield strength, tensile strength and fracture toughness being 600MPa, 900MPa and 40MPam. If the corresponding design safety factors are 1.2, 1.6 and 1.5 respectively. What is the allowable load? (a)Yielding failure (>25 kN) (b)Tensile fracture (>28.1 kN) (c)Fracture toughness (crack size dependant)2 mm: 16.8kN; 1mm: 23.6kN; 0.1mm: 75.2kN
depth of surface defects may be correlated with the richness of color and speed of bleed out -This method depends on the unequal absorption into a porous surface of a liquid containing fine particles in suspension. -Preferential absorption causes the fine particles in the solution to be filtered out and concentrated directly over the crack, producing a visual indication. -A cloud of fine electrically charged particle is blown over the surface, causing a buildup of powder at the defect.
Internal defects detection
Magnetic particle method Radiographic methods Electromagnetic methods Eddy current method
Barkhausen Noise Inspection Principle Material defects (grinding damage, re-tempering burn, Rehardening burn, residue stresses
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Enhancing the penetrant test
Strike the part to force the liquid out of the defect Fluorescent penetrant Filtered-particle inspection:
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Yield strength (plastic deformation)
area = 10 mm x 5 mm = 50 x 10-6 m2 max. load = (yield strength x area) safety factor = (600MPa x 50 x 10-6 m2) 1.2 = 25 kN (plastic deformation at load > 25 kN)
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Fracture Toughness (require information of crack length)
KIC = (a) Assume geometric correction factor, = 1 max = KIC /(a) Max load = x A (safety factor) = KIC /(a) x A (safety factor) = 40MPam /(3.1416 x a) x 50 x 10-6 m2 (safety factor)
Thoroughly clean the surface Apply penetrant on the surface Liquid penetrant enter small openings by capillary action Remove liquid completely and apply developer (dry or wet) The penetant bleed out onto the surface showing the location of the surface defect
Cracks on Non-conducting materials:
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Use to locate the defects at or near the surface of ferromagnetic objects. The magnetic particles tends to pile up and bridge over discontinuities. A surface crack is indicated by a line of the fine particle following the outline of the crack. A subsurface defect by a fuzzy collection of the fine particles on the surface near the defect. Fatigue crack in an airplane gear. Orientation of cracks Some cracks are more difficult to detect. DC current is often employed, since it permit deeper defects detection.