首页
登录
职称英语
[originaltext] Not long ago it was assumed that the dangers man would meet i
[originaltext] Not long ago it was assumed that the dangers man would meet i
游客
2024-04-12
21
管理
问题
Not long ago it was assumed that the dangers man would meet in space would be terrible, the main ones being radiation and the danger of being hit by meteors. It is perhaps worth remembering that less than two’ centuries ago the dangers of train travel seemed similarly terrible. A man would certainly die, it was thought, if carried along at a speed of thirty kilometers per hour.
There are two sorts of radiation man must fear in space. The first is radiation from the sun, and this is particularly dangerous when the sun is very active and explosions are occurring on its surface. The second, less harmful form comes from the so-called Van Allen Belts. These are two areas of radiation about 1,500 miles away from the earth. Neither of these forms of radiation is a danger to us on the earth, since we are protected by our atmosphere. Specifically, it is that part of our atmosphere known as the ozonosphere which protects us. This is a belt of the chemical ozone between 12 and 21 miles from the ground, which absorbs all the radiation.
Once outside the atmosphere, however, man is no longer protected, and radiation can be harmful in a number of ways. A distinction must be drawn between the short- and long-term effects of radiation. The former are merely unpleasant, but just because an astronaut returning from a journey in space does not seem to have been greatly harmed, we cannot assume that he is safe. The long-term effects can be extremely serious, even leading to death.
9 What was one of the main dangers man would meet in space?
10 When is the sun radiation particularly dangerous to human beings?
11 Why did the speaker say neither of these forms of radiation is a danger to us?
选项
A、They are too far away from the earth.
B、Our skin is immune to the radiation.
C、The ozonosphere protects us from it.
D、The trees can absorb the radiation.
答案
C
解析
原文提及“由于地球上的我们被臭氧层保护着。这两种辐射对我们都不造成威胁”。故C正确。
转载请注明原文地址:https://tihaiku.com/zcyy/3551930.html
相关试题推荐
[originaltext]TokyohasreplacedMoscowastheworld’smostexpensivecity
[originaltext]TokyohasreplacedMoscowastheworld’smostexpensivecity
[originaltext]ScoresonEnglishtestsareveryimportanttostudentsaround
[originaltext]ScoresonEnglishtestsareveryimportanttostudentsaround
[originaltext]Thisis4o’clock.Hereisthenewssummary.Therehasbeena
[originaltext]Thisis4o’clock.Hereisthenewssummary.Therehasbeena
[originaltext]Inpublicspeaking,thewatchwordispreparation.Mostofus
[originaltext]W:Roger,anyproblemsinyourKoreanstudy?M:Thebiggestprobl
[originaltext]W:Roger,anyproblemsinyourKoreanstudy?M:Thebiggestprobl
[originaltext]W:Roger,anyproblemsinyourKoreanstudy?M:Thebiggestprobl
随机试题
[A]disabled[I]suffering[B]significantly[J]unhappy[C]related[K]life
OKimiyukiSudashouldbeaperfectcustomerforJapan’scarmakers.He’sayo
Doemployersoragenciesactingon【B1】______ofemployerspostmostofthej
哪些气体筒的压力表所示的压力值并不能代表筒内气体的真正含量()A.二氧化碳
表述教学目标时一般要考虑的因素有()。A.学习者 B.行为 C.条件
A.枸椽酸钠B.草酸钠C.双草酸盐D.肝素E.EDTA-K应选用的抗凝剂分别是血
某乙肝患者,10余年,迁延不愈,是A.血浆凝固酶B.潜伏感染C.链激酶D.胶原酶
甲和同事乙外出吃饭,看到乙的手机从口袋中滑出,但未告知乙。待和乙一起起身离去后,
对于列入《中华人民共和国实施强制性产品认证的产品目录》的出口商品不再实施质量许可
水泥管道的组合结构应构筑在坚实可靠的()上。A.混凝土 B.地基 C.模板
最新回复
(
0
)