首页
财务会计
医药卫生
金融经济
考公考编
外语考试
学历提升
职称考试
建筑工程
IT考试
其他
登录
职称考试
共用题干 Older Volcanic EruptionsVolcanoes were more destructive in ancient hist...
共用题干 Older Volcanic EruptionsVolcanoes were more destructive in ancient hist...
admin
2020-12-24
26
问题
共用题干
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(熔岩)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.
The Permian(二叠纪)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 percent of all marine genera(种类)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 thousand 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(小行星).He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO
2
.
Vincent Courtill.ot,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 tliousands 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。
选项
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.
答案
D
解析
由文章第一段可知,远古火山喷发更具破坏力,不是因为它们规模更大,而是因为它们释放出的二氧化碳更容易毁灭生命。故选A。
由文章第二段第四句话“He calculated the ‘ killing efficiency ' for those… they are produced.”可知,Wignall通过比较火山释放的熔岩的体积与杀死生命的比例计算这些火山的杀伤力。故选D0
由文章第三段倒数第二句话“He ignored the extinction which wiped out the dinosaurs 65 million years ago …”可知,恐龙是在6500万年前灭绝的。故选D。
由文章第三段倒数第二句话“… because many scientists believe it was primarily caused by the impact of an asteroid.”可知,Wignall没有提6500万年前恐龙的灭绝是否跟火山爆发有关是因为许多科学家认为恐龙的灭绝是由一颗小行星的影响造成的。由此可推断出关于恐龙灭绝的原因在科学家之间是有分歧的。故选D。
文章第一段直接点明了文章的主要论点。" Volcanoes were more destructive in ancient history..."(古代火山喷发更具破坏力)。故选B。
转载请注明原文地址:https://ti.zuoweng.com/ti/LJMQKKKQ
相关试题推荐
共用题干 EconomicReforminChinaMoreUSsinologistshaveexpressedconfidencei...
共用题干 EconomicReforminChinaMoreUSsinologistshaveexpressedconfidencei...
共用题干 EconomicReforminChinaMoreUSsinologistshaveexpressedconfidencei...
共用题干 EconomicReforminChinaMoreUSsinologistshaveexpressedconfidencei...
共用题干 EconomicReforminChinaMoreUSsinologistshaveexpressedconfidencei...
共用题干 EconomicReforminChinaMoreUSsinologistshaveexpressedconfidencei...
共用题干 EconomicReforminChinaMoreUSsinologistshaveexpressedconfidencei...
共用题干 TheJoyofLivingAloneMoreandmoreAmericansarelivingalone.Someli...
共用题干 TheJoyofLivingAloneMoreandmoreAmericansarelivingalone.Someli...
共用题干 TheJoyofLivingAloneMoreandmoreAmericansarelivingalone.Someli...
随机试题
灌注水下混凝土,导管使用前应进行()。 A、承压和抗压试验 B、气密承压和接
经济订货批量的计算需要考虑的因素有()。
胸水中葡萄糖含量显著下降的情况常见于
患者,女,32岁,右侧前部牙齿有龋洞,遇冷热水不适半年余,近来工作紧张,症状较前加重,热食引起痛,夜间时而感到隐痛,有夜磨牙习惯。该患者最可能的牙病是(
《铁路机车运用管理规则》规定:()负责日常安全信息收集、汇总、分析和上报等管理工作;参与事故调查和分析,并制定整改措施。A.机务段B.运用科C.安全科D
我国对事业单位实行“核定收支”,其中的“收”是指()。A.仅限于财政补助收入B.仅限于非财政补助收入C.事业单位的自营收入D.包括财政补助和非财政补助收入
(2013年)预算定额中人工、材料、机械台班消耗量的确定方法包括()。A.以施工定额为基础确定B.以现场观察测定资料为基础计算C.以工程量计算规则为依据计算
级配碎石适用于各级公路的()。A.基层B.面层C.下面层D.上面层E.底基层
单位工程质量控制资料检查记录表的签字人有()。A.施工单位技术负责人B.施工单位项目负责人C.总监理工程师D.建设单位项目负责人E.设计单位项目负责人
关于侦查中的检查与搜查,下列哪一说法是正确的?A:搜查的对象可以是活人的身体,检查只能对现场、物品、尸体进行B:搜查只能由侦查人员进行,检查可以由具有专门知识