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
49
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
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.
答案
A
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/pJMQKKKQ
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
常用来反映股票基金风险的指标有( )。 Ⅰ.持股数量 Ⅱ.贝塔系数 Ⅲ.持
从财务管理的角度,可以将金融市场划分为()。 Ⅰ.债务证券市场 Ⅱ.权益证券
公司理财业务主要包括()。
微量元素
甲、乙两条生产线均生产一种规范阻值为100±5Ω的电阻器,其电阻值X甲与X乙分别
为了切实做到尊重患者自主性决定,医生向患者提供信息时要避免()A.诱导B.适度C.适量D.理解E.开导
刻板动作的特点是()。 (A)反复地重复某一动作(B)动作违背个人意愿 (C)常伴随有刻板的言语(D)能体验到内心痛苦
基因能控制生物的性状,转基因技术是将一种生物的基因转入另一种生物中,使被转入基因的生物产生人类所需要的性状。这种技术自产生之日起就备受争议。公众最关心转基...
下列各项中,不属于胎黄病因病机的是A:脾肾阳虚B:脾胃湿热C:寒湿内蕴D:气滞血瘀E:肝失疏泄
钟状期的成釉器不包括哪种()。A.外釉上皮B.内釉上皮C.星网状层D.中间层E.成牙本质细胞层