资源预览内容
第1页 / 共19页
第2页 / 共19页
第3页 / 共19页
第4页 / 共19页
第5页 / 共19页
第6页 / 共19页
第7页 / 共19页
第8页 / 共19页
第9页 / 共19页
第10页 / 共19页
亲,该文档总共19页,到这儿已超出免费预览范围,如果喜欢就下载吧!
资源描述
试卷说明:红色代表正确选项(供参考)第1部分:词汇选项(第115题,每题1分,共15分)下面每个句子中均有1个词或者短语有括号,请为每处括号部分确定1个意义最为接近的选项。1. The rules are too (rigid) to allow for human error.A. inflexibleB. generalC. complexD. direct2. This species has nearly (died out) because its habitat is being destroyed.A. turned deadB. passed byC. carried awayD. become extinct3. The contract between the two companies will (expire) soon.A. shortenB. endC. startD. resume4. Three world-class tennis players came to (content) for this title.A. argueB. claimC. wishD. compete5. The methods of communication used during the war were (primitive).A. simpleB. reliableC. effectiveD. alternative6. Respect for life is a (cardinal) principle of the law.A. moralB. regularC. fundamentalD. hard7. The drinking water has became (contaminated) with lead.A. pollutedB. treatedC. testedD. corrupted8. Come out, or Ill (bust) the door down.A. shutB. setC. breakD. beat9. She (shed) a few tears at her daughters wedding.A. wipedB. injectedC. producedD. removed10. They didnt seem to appreciate the (magnitude) of the problem.A. existenceB. importanceC. causeD. situation11. The tower remains (intact) ever after two hundred years.A. unknownB. unusualC. undamagedD. unstable12. Many experts remain (skeptical) about his claims.A. doubtfulB. untouchedC. certainD. silent13. The proposal was (endorsed) the majority of members.A. rejectedB. submittedC. consideredD. approved14. Rumors began to (circulate) about his financial problems.A. sendB. spreadC. hearD. confirm15. The police will need to keep a (wary) eye on this area of town.A. nakedB. cautiousC. blindD. private答案:1-5:A D B D A;6-10:C A C C B ; 11-15:C A D B B第2部分:阅读判断(第1622题,每题1分,共7分)下面的短文后列出了7个句子,请根据短文的内容对每个句子做出判断;如果该句提供的是正确信息,请选择A;如果该句提供的是错误信息,请选择B;如果该句的信息文中没有提及,请选择C。New Understanding of Natural Silks MysteriesNatural silk, as we all know, has a strength that manmade materials have long struggled to match. In a discovery that sounds more like an ancient Chinese proverb than a materials science breakthrough, MIT researchers have discovered that silk gets its strength from its weakness. Or, more specifically, its many weaknesses. Silk gets its extraordinary durability and ductility from an unusual arrangement of hydrogen bonds that are inherently very weak but that work together to create a strong, flexible structure.Most materials - especially the ones we engineer for strength - get their toughness from brittleness. As such, natural silks like those produced by spiders have long fascinated both biologists and engineers because of their light weight, ductility and high strength (pound for pound, silk is stronger than steel and far less brittle). But on its face, it doesnt seem that silks should be as strong as they are; molecularly, they are held together by hydrogen bonds, which are far weaker than the covalent bonds found in other molecules.To get a better understanding of how silk manages to produce such strength through such weak bonds, the MIT team created a set of computer models that allowed them to observe the way silk behaves at the atomic level. They found that the arrangement of the tiny silk nanocrystals is such that the hydrogen bonds are able to work cooperatively, reinforcing one another against external forces and failing slowly when they do fail, so as not so allow a sudden fracture to spread across a silk structure.The result is natural silks that can stretch and bend while retaining a high degree of strength. But while thats all well and good for spiders, bees and the like, this understanding of silk geometry could lead to new materials that are stronger and more ductile than those we can currently manufacture. Our best and strongest materials are generally expensive and difficult to produce (requiring high temperature treatments or energy-intensive processes).By looking to silk as a model, researchers could potentially devise new manufacturing methods that rely on inexpensive materials and weak bonds to create less rigid, more forgiving materials that are nonetheless stronger than anything currently on offer. And if you thought you were going to get out of this materials science story without hearing about carbon nanotubes, think again. The MIT team is already in the lab looking into ways of synthesizing silk-like structures out of materials that are stronger than natural silk - like carbon nanotubes. Super-silks are on the horizon.参考译文:我们都知道,蚕丝具有的韧性是人造织物长期奋力追求的目标。在一项研究中(该项研究成果听起来更像一则古代中国谚语,而不是材料科学的突破),麻省理工学院的研究人员发现,蚕丝的力量源于其脆弱,或者,更具体地说,是它的多方面的脆弱。蚕丝的异常耐久性和延展性来自一种特别的氢键结构,这些氢键本质上非常脆弱,但它们共同创造了一种强壮而富有弹性的结构。大多数材料(特别是那些要求硬度很高的材料)的韧性来自脆性。因此,和蜘蛛制造的蛛丝类似的蚕丝,因其重量轻,延展性强和韧性高,长期以来引起了生物学家和工程
收藏 下载该资源
网站客服QQ:2055934822
金锄头文库版权所有
经营许可证:蜀ICP备13022795号 | 川公网安备 51140202000112号