2015年6月大学英语六级模拟试题(2)

　　根据下面材料，回答57-61题。

　　University of York biologist Peter Mayhew recently found that global warming might actually increase the number of species on the planet，contrary to a previous report that highertemperatures meant fewer life forms—a report mat was his own.

　　In Mayhew’s initial 2008 study，low biodiversity among marine invertebrates(无脊椎动物)appeared to coincide with warmer temperatures on Earth over the last 520million years. But Mayhew and his colleagues decided to reexamine their hypothesis，this time usingdata that were“a fairer sample of the history of life.”砌this new collection of material.theyfound a complete reversal of the relationship between species richness and temperature from whattheir previous paper argued：the number of different groups present in the fossil record washigher，rather than lower，durin9“greenhouse phases.”

　　Their previous findings rested on an assumption that fossil records can be taken to represent biodiversity changes throughout history.Thisn’t necessarily the case.because there arecertain periods with higher.quality fossil samples.and some that are much more difficult to samplewell.Aware of this bias.Mayhew’s team used data that standardized the number of fossils examinedthroughout history and accounted for other variables like sea level changes that might influencebiodiversity in their new study to see if their old results would hold up.

　　Two years later，the results did not.But then why doesn't life increasingly emergeon Earth as our temperatures get warmer?While the switch may prompt some to assert that climatechange is not hazardous to living creatures，Mayhew explained that the timescales in his team’sstudy are huge--over 500million years--and therefore inappropriate for the shorter periods that wemight look at as humans concerned about global wanning.Many global warming concerns are focused onthe next century.He said——and the lifetime of a species is typically one to 10 million years. “I do worry that these findings vill be used by the climate skeptic community to say‘look.Climate warming is fine。he said.Not to mention the numerous other things we seem to doto create a storm of threats to biodiversity—think of what habitat(栖息地)destruction，overfishing，and pollution can do for a species’viability(生存力).Those things，Mayhew explained，give the organisms a far greaterchallenge in coping with climate change than they would have had in the absence of humans. “If we were to relax all these pressures on biodiversity and allow the world to

　　57What is the finding of Peter Mayhew’s recent study?

　　A. Higher temperature causes the low biodiversity of marine invertebrates.

　　B. Fossil record can represent a relatively believable history of life.

　　C. The number of fossils was higher during greenhouse phases.

　　D. Global warming might promote the richness of species on Earth.

　　58What do we learn about Mayhew’s previous report?

　　A. It was based on his colleagues’hypothesis about global warmin9.

　　B. It was contrary to what his team found in the recent study.

　　C. It was a complete reversal from his 2008 study about marine invertebrates.

　　D. It found evidence for the connections between biodiversity and temperature.

　　59Why does Mayhew’s team use data that standardized the number of fossils?

　　A. They realize not all fossils can sample well to represent biodiversity changes.

　　B. They start to consider the variables that might influence biodiversity.

　　C. They want to check the previous findings with different research methods.

　　D. They believe sea level changes can lead to inaccurate fossil records.

　　60Because of the huge timescales in his study，Mayhew believed .

　　A. global warming is not hazardous t0 1iving creatures in a short time

　　B. his study is not suitable to support short-term global warming

　　C. global warming concerns should be focused on in the next century

　　D. the lifetime of a species can be extended t0 10 million years

　　61By“we don’t have 500 million years to wait”(Line 4，Para.6)，the author suggests that_____.

　　A. we have no enough time to allow the earth to recover from damages

　　B. we have no enough time to witness the evolution of a species

　　C. it’s urgent for humans to take steps to prevent global warming

　　D. it's necessary for humans to stop maltreatment of the planet