职称英语（综合类）模拟试题（五）
4 The Permian extinction, for example, which happened 250 million years ago, is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe. Those volcanoes are thought to have pumped out about 10 gigatonnes of carbon as carbon dioxide. The global warming that followed wiped out 80 per cent of all marine genera at the time. And it took 5 million years for the planet to recover.
5 Yet 60 million years ago in the late Palaeocene there was another huge amount of volcanic activity and global warming but no mass extinction. Some animals did disappear but things returned to normal within ten thousands of years, "The most recent ones hardly have an effect at all," Wignall says. He ignored the extinction which wiped out the dinosaurs at the end of the Cretaceous, 65 million years ago, because many scientists believe it was primarily caused by the impact of an asteroid.
6 Wignall thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2. Ocean chemistry may also have played a role．As the supercontinents broke up and exposed more coastline there may have been more weathering of silica rocks. This would have encouraged the growth of phytoplankton in the oceans, increasing me amount of CO2 absorbed from the atmosphere.
7 Vincent Courtillot, director of the Paris Geophysical Institute in France, says that Wignalls idea is provocative. But he says it is incredibly hard to do these sorts of calculations. He points out that the killing power of volcanic eruptions depends on how long they lasted. And it is impossible to tell whether the huge blasts lasted for thousands or millions of years.
8 Courtillot also adds that it is difficult to estimate how much 1ava prehistoric volcanoes produced, and that 1ava volume may not necessarily correspond to carbon dioxide or sulphur dioxide emissions.
23．Paragraph 2 _____________(www.xuehuiba.com)版权所有www.xuehuiba.com
24．Paragraph 3 _____________
25．Paragraph 4 _____________
26．Paragraph 5 _____________
A Killing Power of Ancient Volcanic Eruptions
B Association of Mass Extinctions with Volcanic Eruptions
C Calculation of the Killing Power of Older Eruptions
D A Mass Extinction
E Volcanic Eruptions That Caused no Mass Extinction
F Accounting for the Killing Power of Older Eruptions
27．Older eruptions were more devastating _____________.
28．The Permian extinction is used to illustrate __________.
29．The cause of the extinction of dinosaurs ____________.
30．Courtillot rejects _______________________________.
A than more recent ones
B the killing efficiency for older eruptions
C has remained controversial
D Wignalls calculations as acceptable
E has been known to us all
F his ideas
3.阅读理解（一）
Forty May Be the New 30 as Scientists Redefine Age
Is 40 really the new 30? In many ways people today act younger than their parents did at the same age.
Scientists have defined a new age concept and believe it could explain why populations are aging, but at the same time seem to be getting younger.
Instead of measuring aging by how long people have lived, the scientists have factored in how many more years people can probably still look forward to.
“Using that measure, the average person can get younger in the sense that he or she can have even more years to lives as time goes on,” said Warren Sanderson of the University of New York in Stony Brook.
He and Sergei Scherbov of the Vienna Institute of Demography （人口统计学）at the Austrian Academy of Sciences, have used their method to estimate how the proportion of elderly people in Germany, Japan and the United States will change in the future.
The average German was 39.9 years old in 2000 and could plan to live for another 39.2 years, according to research reported in 2050 would occur at around 52 years instead of 40 years as in 2000.
“As people have more and more years to live they have to save more and plan more and they effectively are behaving as if they were younger,” said Sanderson.
Five years ago, the average American was 35.3 years old and could plan for 43.5 more years of life. By 2050, the researchers estimate it will increase to 41.7 years and 45.8 future years.
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