首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Blasts from the Past 1.Volcanoes were destructive in ancient history. Not because they were bigger, but because the carbon di
Blasts from the Past 1.Volcanoes were destructive in ancient history. Not because they were bigger, but because the carbon di
admin
2010-01-13
46
问题
Blasts from the Past
1.Volcanoes were destructive in ancient history. Not because they were bigger, but because the carbon dioxide they released wiped out life with greater ease.
2.Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions. Not all volcanic eruptions killed off large number of animals, but all the mass extinction cover 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.
3.Wignall 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 size for size, older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.
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, 265 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 the amount of CO2absorbed from the atmosphere.
7.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.
8.Courtillot 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 or sulphur dioxide emissions.
A.Killing Power of Ancient Volcanic Eruptions
B.Association of Mass Extinctions with Volcanic
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
选项
答案
B
解析
第二段的第一句话是这么说的:Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.利兹大学的Paul Wignall正在研究火山爆发与物种大量灭绝的联系。the association of mass extinctions with volcanic eruptions与the link between voleanic eruptions and mass extinctions在意思上是相同的。
转载请注明原文地址:https://kaotiyun.com/show/zCGd777K
本试题收录于:
职称英语综合类基础题库职称英语分类
0
职称英语综合类基础
职称英语
相关试题推荐
SingingAlarmsCouldSavetheBlindIfyoucannotsee,youmaynotbeabletofindyourwayoutofaburningbuilding-andtha
TheauthorcouldnotgotosleeppartlybecauseGladiatorwasthenameof
Accordingtothepassage,someengineersaretryingtoimprovethehandlebarsbecause______.Paragraph3mainlydiscusses____
SaveEnergyatHomeOntheaverage,Americanswasteasmuchenergyastwo-thirdsoftheworld’spopulationconsumes.That’s
Indonesiawasincrisisbecauseofthedrought.ManyIndonesiansblamedthegovernmentforthedrought.
Thelocalgovernmentplannedtolaunchanewprogramtohelpthepoor.
WhatisChineseNewYear?InmanypartsofAsia,nationsfollowthelunarcalendarratherthantheGregoriancalendarusedb
WhyBuyShade-GrownCoffee?Whenpeopleargueaboutwhethercoffeeisgoodforhealth,they’reusuallythinkingofthehealt
AindustriallypollutedsoilsBrockandsoilchemistryCnaturallypollutedsoilsDthepathwaysofmetalsintothefoodchain
"Salty"RicePlantBoostsHarvestsBritishscientistsarebreedinganewgenerationofriceplantsthatwillbeabletogrowin
随机试题
目前居我国孕产妇死亡原因首位的是()
长于温中降逆,兼能温肾助阳的药是
2004年3月3日,某自来水公司发布了一个文件,称以后凡需要安装自来水管的建筑工程,须按其指定到某机电公司购买铺设自来水管道所需要的水龙头等设备,然后拿着购买单据到自来水公司申请供水。对此不正当竞争行为,谁有权对其进行行政处罚?
以下关于利用干湿球温度计测量相对湿度的叙述,错误的是()。
某跨年度项目的合同总收10000万元,预计合同总成本8500万元,资产负债表日,以前会计年度累计已确认的收入为6000万元,该工程现已完成工程进度的80%,则当期应确认的合同收入为()万元。
银行业金融机构完成整改,经验收符合有关审慎经营规则时.监管部门应当自验收完毕之日起()内解除对其采取的有关措施,防止监管机构滥用监督管理权力。
某生产企业,2008年有关会计资料如下: (1)年度会计利润总额为300万元; (2)全年销售收入为3000万元; (3)“管理费用”中列支的业务招待费30万元,广告费和业务宣传费500万元: (4)“营业外支出”中列支的税收罚款1万元,公
下列关于与专家达成一致意见的说法中,不正确的是()。
提笔忘字,考试时回忆不出有关的知识,一出考场就能想起来,这是()现象。
根据图片上的内容。结合日后的警察工作,谈谈你的看法。
最新回复
(
0
)