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职称英语测验浏览懂得专项操练《卫生A》
莫等闲，白了少年头，空悲切。以下是小编为大师搜刮清算的职称英语测验浏览懂得专项操练《卫生A》，但愿能给大师带来赞助!更多出色内容请实时存眷咱们应届毕业生测验网!
Older Volcanic Eruptions
Volcanoes were more destructive in ancient history, not because they were bigger, but because the carbon dioxide they released wiped out life with greater ease.
Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions. Not all volcanic eruptions killed off large numbers of animals, but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock. To his surprise, the older the massive volcanic eruptions were, the more damage they seemed to do. He calculated the "killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava that they produced. He found that for size, older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.
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 gigatones of carbon as carbon dioxide. The global warming that followed wiped out 80 percent of all marine genera at the time, and it took 5 million years for the planet to recover. Yet 60 million years ago, 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 65 million years ago, because many scientists believe it was primarily caused by the impact of an asteroid. He thinks that older volcanoes had more killing power because more recent life forms 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 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. He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced, and that lava volume may not necessarily correspond to carbon dioxide emissions.
1.Why did older volcanic eruptions do more damage than more recent ones?
A. Because they killed off life more easily.
B. Because they were brighter.
C. Because they were larger.
D. Because they were hotter.
2.How did Wignall calculate the killing power of those older volcanic eruptions?
A. By estimating how long they lasted.
B. By counting the dinosaurs they killed.
C. By studying the chemical composition of lava.
D. By comparing the proportion of life wiped out with the volume of lava produced.
3.When did dinosaurs become extinct?
A. 300 million years ago.
B. 250 million years ago.
C. 60 million years ago.
D. 65 million years ago.
4. What can be inferred from paragraph 3 concerning dinosaurs?
A. They were killed off by an asteroid.
B. They died of drastic climate change.
C. They were wiped offby a volcanic eruption.
D. The cause of their extinction has remained a controversial issue.
5.What is the main thesis of the article?
A. Volcanic eruptions are not always deadly.
B. Older volcanic eruptions were more destructive.
C. Carbon dioxide emissions often give rise to global warming.
D. It is not easy to calculate the killing power of a volcanic eruption.
谜底剖析
1.A。细节题。题干：为甚么太古的火山迸发比近期的火山迸发粉碎性更大?操纵题干关头词能够定位到第一段：现代的火山更具粉碎力，不是由于它们更大，而是由于它们开释出的二氧化碳更能等闲地扑灭性命。
2.D。细节题。题干：Wignall是若何计较出太古火山迸发的杀伤力的?操纵题干关头词能够定位到第二段。第二段有如许一句话：He calculated the“killing efficiency'’for these volcanoes by comparing the proportion oflife they killed offwith the volume oflava that they produced.(他经由过程比拟火山开释出的熔岩的体积与杀死性命的比例计较这些火山的杀伤力)。
3.D。细节题。题干：恐龙是甚么时辰灭尽的?操纵题干关头词能够定位到第三段。此中有这么一句话：He ignored the extinction which wiped out the dinosaurs 65 million years ago，because many scientists believe it was primarily caused by the impact ofan asteroid.(他不说起6500万年前恐龙的灭尽，由于很多迷信家信任恐龙的灭尽是受一颗小行星的影响)。
4.D。细节题。题干：从第三段还能够推导出有关恐龙的.甚么样的信息?在会商第三题的谜底时，咱们已注重到了，Wignall不提6500万年前恐龙的灭尽是不是跟火山迸发有关，由于很多迷信家信任恐龙的灭尽是受一颗小行星的影响。这就申明，对于恐龙灭尽的缘由在迷信家之间是有争议的。
5.B。大旨题。题目问的是：文章的首要论点是甚么?谜底在文章的第一句：Volcanoes were more destructive in ancient history(现代火山更具粉碎力)。
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