大学英语六级仔细阅读练习题
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. ButMayhew and his colleagues decided to reexamine their hypothesis，this time using data thatwere“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 what theirprevious 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 representbiodiversity changes throughout history.Thisn’t necessarily the case.because there are certainperiods 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 fossilsexamined throughout history and accounted for other variables like sea level changes that mightinfluence 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 on Earth asour temperatures get warmer?
While the switch may prompt some to assert that climate change is not hazardous to livingcreatures，Mayhew explained that the timescales in his team’s study are huge--over 500millionyears--and therefore inappropriate for the shorter periods that we might look at as humansconcerned about global wanning.Many global warming concerns are focused on the nextcentury.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 we seem todo 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.
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
Passage Two
Questions 61 to 65 are based oil the following passage.
Uke a tired marriage.the relationship between libraries and publishers has long beenreassuringly dull.E—books，however，are causing heartache.
Libraries know they need digital wares if they are to remain relevant，but many publishers aretoo careful about piracy and lost sales to c0.operate.Among the big six.only Random Houseand HarperCollins license e-books with most libraries.The others have either denied requests orare reluctantly experimenting.
Publishers are wise to be nervous.Owners of e.readers are exactly the customers theyneed：book—lovers with money-neither the devices nor broadband connections come cheap.Ifthese wonderful people switch to borrowing e-books instead of buying them，what then?
Electronic borrowing is awfully convenient.Unlike printed books.which must be checked outand
returned to a physical library miles from where you live，book files can be downloaded athome.Digital library catalogues are often browsed at night.from a comfortable sofa.The filesdisappear from the device when they are due.
Awkwardly for publishers，buying an e—book costs more than renting one but offers little extravalue.
You cannot resell it。lend it to a friend or burn it to stay warm.Owning a book is useful if youwant to savor(品尝)it repeatedly，but who reads“Fifty Shades of Grey”twice?
E-1ending is not simple.however.There are lots of different and often incompatible e-bookformats，devices and licences.Most libraries use a company called Over Drive，a global distributorthat secures rights from publishers and provides e-books and audio files in every format.Yetpublishers and libraries are worried by Over Drive’s market dominance，as the company canincreasingly dictate fees and conditions.
Library boosters argue that book borrowers are also book buyers，and that libraries are vitalspaces for readers to discover new work.Many were.cheered by a recent Pew survey，whichfound that more than half of Americans with Horary cards say they prefer to buy their e-books.Butthe report also noted that few people know that e-books are available at most libraries，and thatpopular titles often involve long waiting lists，which may be what inspires people to buy.
So publishers keep adjusting their lending arrangements in：search of the rightbalance.Random House raised its licensing prices earlier this year，and Harper Collins limits librariesto lending its titles 26 times.
Hachita is engaged in some secret experiments，and the others are watching with heldbreath.In Britain the government will soon announce a review of the matter.The story of thelibrary e-book is a nail-biter.
61.What can be inferred from the fast paragraph?
A.Libraries are eager to keep relationship with publishers.
B.Several publishers have sold e-books to most libraries.
C.Libraries care too much about piracy and book sales.
D.Most publishers hesitate to cooperate with libraries.
62.What does the author say about electronic borrowing?
A.It call help save readers’expenses on devices and broadband connections.
B.It needs checking out and returning to the library via the Intemet.
C.It enables readers to resell the book files or lend them to friends.
D.It has a time limit for the book files downloader on the device.
63.What do we learn about Over Drive?
A.It has the privilege to offer readers various brands of e-readers.
B.It distributes e-books and audio files to publishers.
C.Its market dominance threatens publishers and libraries.
D.It devotes itself to improving conditions of e.book market.
64.According to the recent Pew survey，_____.
A.more than half of Americans choose e-books over physical copies
B.people with library cards advocate borrowing rather than buying books
C.people with library cards have to wait to borrow popular e-books
D.the desire to collect a popular book inspires people to buy it
65.By“a nail-biter”(Line 4，Para.7)，the author suggests that_____.
A.it’s urgent for Librairies to cooperate with publishers
B.publishers have many secret experiments to conduct
C.it’s impossible for publishers to distribute e-books to libraries
D.many problems about e-book lending need to be solved