2017理工类职称英语练习

　　The Permian (二叠纪)extinction, for example, which happened 250 million years ago, is marked byfloods of volcanic rock in Siberia that cover an area roughly the size ofwestern Europe. Those volcanoes are thought to have pumped out about 10gigatonnes (十亿吨) of carbon as carbon dioxide. The globalwarming that followed wiped out 80 percent of all marine genera (种类)at the time, and it took 5 million years for the planet to recover. Yet 60million years ago, there was another huge amount of volcanic activity andglobal warming but no mass extindtion. Some animals did disappear but thingsreturned to normal within tens of thousands of years. "The most recentones hardly have an effect at all," Wignall says. He ignored theextinction which wiped out the dinosaurs (恐龙) 65million years ago, because many scientists believe it was primarily caused bythe impact of an asteroid (小行星). Hethinks that older volcanoes had more killing power because more recent lifeforms were better adapted to dealing with increased levels of CO2.

　　Vincent Courtillot, director of the Paris Geophysical Institute in France,says that Wignall's idea is provocative. But he says it is incredibly hard todo these sorts of calculations. He points out that the killing power ofvolcanic eruptions depends on how long they lasted. And it is impossible totell whether the huge blasts lasted for thousands

　　or millions of years. He also adds that itis difficult to estimate how much lava prehistoric volcanoes produced, and thatlava volume may not necessarily correspond to carbon dioxide emissions.

　　41.Older volcanic eruptions did moredamage than more recent ones because

　　A. older volcanoes were brighter.

　　B. carbon dioxide made the earth muchwarmer

　　C. older volcanoes were hotter

　　D. carbon dioxide killed off life moreeasily

　　答案：d

　　42. Wignall calculated the killing powerof those older volcanic eruptions by

　　A. estimating how long they lasted

　　B. counting the dinosaurs they killed

　　C. comparing the proportion of lifekilled with the volume of lava produced

　　D. studying the chemical composition oflava

　　答案：c

　　43. When did dinosaurs become extinct?

　　A. 300 million years ago.

　　B. 250 million years ago

　　C. 65 million years ago

　　D. 60 million years ago

　　答案：c

　　44. It can be inferred from Paragraph 3that the cause of dinosaur extinction is_______

　　A. a political issue.

　　B. self-evident.

　　C. quite certain

　　D. controversial

　　答案：d

　　45. What is the main thesis of thearticle?

　　A. Volcanic eruptions are not alwaysdeadly.

　　B. Carbon dioxide emissions often giverise to global warming.

　　C. Older volcanic eruptions are moredestructive

　　D. It is not easy to calculate the killingpower of a volcanic eruption

　　答案：c

　　第四部分补全短文

　　Researchers Discover Why Humans Began Walking Upright

　　Most of us walk and carry items in our hands every day. These are seemingly simple activities that the majority of us don’t question. But an international team of researchers, including Dr. Richmond from GW's Columbian College of Arts and Sciences，have discovered that human walking upright, may have originated millions of years ago as an adaptation to carrying scarce, high- quality resources. The team of researchers from the U. S., England, Japan and Portugal investigated the behavior of modern-day chimpanzees as they competed for food resources，in an effort to understand what ecological settings would lead a large ape — one that resembles the 6 million-year old ancestor we shared in common with living chimpanzees — to walk on two legs.

　　“These chimpanzees provide a model of the ecological conditions under which our earliest ancestors might have begun walking on two legs, "，said Dr. Richmond.

　　The research findings suggest that chimpanzees switch to moving on two limbs instead of four in situations where they need to monopolize a resource. Standing on two legs allows them to carry much more at one time because it frees up their hands. Over time，intense bursts of bipedal activity may have led to anatomical changes that in turn became the subject of natural selection where competition for food or other resources was strong.

　　Two studies were conducted by the team in Guinea. The first study was conducted by the team in Kyoto University’s “ outdoor laboratory ” in a natural clearing in Bossou Forest. Researchers allowed the wild chimpanzees access to different combinations of two different types of nut — the oil palm nut，which is naturally widely available, and the coula nut, which is not. The chimpanzees’ behavior was monitored in three situations:(a) when only oil palm nuts were available,(b)when a small number of coula nuts were available，and(c) when coula nuts were the majority available resource.

　　When the rare coula nuts were available only in small numbers, the chimpanzees transported more at one time. Similarly, when coula nuts were the majority resource, the chimpanzees ignored the oil palm nuts altogether. The chimpanzees regarded the coula nuts as a more highly-prized resource and competed for them more intensely.

　　In such high-competition settings，the frequency of cases in which the chimpanzees started moving on two legs increased by a factor of four. Not only was it obvious that bipedal movement allowed them to carry more of this precious resource, but also that they were actively trying to move as much as they could in one go by using everything available 一 even their mouths.

　　The second study, by Kimberley Hockings of Oxford Brookes University, was a 14-month study of Bossou chimpanzees crop-raiding, a situation in which they have to compete for rare and unpredictable Resources. Here, 35 percent of the chimpanzees activity involved some sort of bipedal movement, and once again, this behavior appeared to be linked to a clear attempt to carry as much as possible at one time.

　　参考答案： BAEFC

　　完形填空

　　CellPhone Lets Your Secrets Out

　　Your cell phone holds secrets about you.Besides the names and numbers that you've programmed into it, ______traces____(51) of your DNA linger (遗留) on thedevice according to a new study

　　DNA is genetic (遗传的)material _____that_____ (52) appears in every cell. Like your fingerprint, yourDNA is _____unique______ (53) to you——unless you have an identical twin. Scientiststoday analyze DNA in blood, saliva (唾液), orhair left ____behind_______ (54) at the scene of a crime. The results oftenhelp detectives identify ____criminals______ (55) and their victims. Your cellphone can reveal more about you ____than_____ (56) you might think.

　　Meghan J. McFadden, a scientist at McMasterUniversity in Hamilton, Ontario, heard about a crime in which the suspect bledonto a cell phone and later dropped the____device_____ (57). This made herwonder whether traces of DNA lingered on cell phones一evenwhen no blood was___involved_____(58). She and colleague Margaret Wallace ofthe City University of NewYork analyzed the flip-open phones(翻盖手机)of10 volunteers. They used swabs (药签) tocollect _____invisible___ (59) traces of the users from two parts of the phone:the outside, where the user ____holds_____(60) it, and the speaker which isplaced at the user's ear

　　The scientists cleaned the phones using asolution made mostly__of____(61) alcohol. The aim of washing was to remove alldetectable traces of DNA. The owners got their phones back for another week.Then the researchers ___returned________ (62) the phones and cleaned each phoneonce more.

　　The scientists discovered DNA that _____belonged______(63) to the phone's speaker on each of the phones. Better samples werecollected from the outside of each phone, but those swabs also picked up DNAthat belonged to other people who had apparently also ____handed______ (64) thephone

　　Surprisingly, DNA showed up even in swabsthat were taken immediately after the phones were scrubbed. That suggests thatwashing won't remove all traces of ___evidence________ (65) from a criminal'sdevice. So cell phones can now be added to the list of clues that can clinch (确定)a crime-scene investigation.

　　51. A. name B.pictures C. shapes D. traces

　　答案：d

　　52. A. that B. while C.as D.what

　　答案：a

　　53. A. common B. good C. helpful D. unique

　　答案：d

　　54. A. behind B. away C. aside D.over

　　答案：a

　　55. A. visitors B. travelers C.scientists D.criminals

　　答案：d

　　56. A. until B. before C.unless D. than

　　答案：d