Questions 56 to 60 are based on the followingpassage.

University of York biologist Peter Mayhew recentlyfound that global warming might actually increasethe number of species on the planet，contrary toa previous report that higher temperatures meantfewer 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 520 million years.But Mayhew and his colleagues decided to reexamine their hypothesis，this time using datathat were“a fairer sample of the history of life.”砌this new collection of material.they found acomplete 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 torepresent biodiversity changes throughout history.Thisn’t necessarily the case.because thereare certain periods with higher.quality fossil samples.and some that are much more difficultto sample well.Aware of this bias.Mayhew’s team used data that standardized the number offossils examined throughout history and accounted for other variables like sea level changesthat might influence biodiversity 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 emerge onEarth as our temperatures get warmer?

While the switch may prompt some to assert that climate change is not hazardous toliving creatures，Mayhew explained that the timescales in his team’s study are huge--over500million years--and therefore inappropriate for the shorter periods that we might look at ashumans concerned about global wanning.Many global warming concerns are focused on thenext 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 tosay‘look.Climate warming is fine。he said.Not to mention the numerous other things weseem to do to 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).Thosethings，Mayhew explained，give the organisms a far greater challenge in coping with climatechange 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 recover overmillions of years in a warmer climate.then my prediction is it would be an improvement inbiodiversity，”he said.So it looks like we need to curb our reckless treatment of the planetfirst，if we want to eventually see a surge in the number of species on the planet astemperatures get warmer.We don’t have 500 million years to wait.英语六级试题

56.What 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.

57.What do we learn about Mayhew’s previous report?

A.It was based on his colleagues hypothesis about global warming.

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.

58.Why 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.

59.Because 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

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

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

参考答案

56.D)。本题考查彼得·梅休的最新研究成果。定位句指出，他发现气候变暖可能使得地球上物种的数量增加，故答案为D)。

57.B)。本题考查对梅休之前研究报告结论的理解。定位句指出，在新收集的材料中，他们发现了与他们之前的论文所辩称的一种物种丰富性与温度间完全相反的关系，故答案为B)。

58.A)。本题考查梅休团队利用标准化化石的原因。定位句指出，因为某些特定的时段有一些更高质量的化石样本，其中一些更难取出好的样本。基于这一点，梅休团队在他们的新实验中利用标准化个数并被历史所检测的化石数据，故本题答案为A)。

59.B)。本题考查梅休对于研究时间跨度太长的态度。定位句指出，梅休解释他们团队的研究时标很长，有5亿多年，所以用于解释人们关注的较短时间内的全球变暖是不合适的，故答案为B)。

60.D)。