首页
登录
职称英语
What forms of radiation are feared by astronauts? [originaltext] Not long ag
What forms of radiation are feared by astronauts? [originaltext] Not long ag
游客
2023-11-21
29
管理
问题
What forms of radiation are feared by astronauts?
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 per- haps 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 area is dangerous 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.
选项
A、Radiation from the sun.
B、Radiation from the Van Allen Belts.
C、Radiation from the meteors.
D、Both A and B.
答案
D
解析
听遍全文我们知道“There are two sorts of radiation man must fear in space.”“The first is radiation from the sun”“The second,less harmful form comes from the so-called Van Allen Belts”,因此宇航员们所惧怕的就是这两种射线。
转载请注明原文地址:https://tihaiku.com/zcyy/3207289.html
相关试题推荐
[originaltext]M:Goodevening,everybody.[6]Nomophobiaisatermwecameacro
[originaltext]M:I’mAviArditti,andthisweekonWordmaster:[1]alessonin
[originaltext]W:Nowweturntooneoftheintervieweestogiveusmoreinforma
[originaltext]W:[1]Eachyear,approximatelyonemillionstudentsdropoutof
[originaltext]W:Oneofthoseministerswhohadtogointothechambertovote
[originaltext]M:Theconceptthatyoucanearnahighsalarywithouthavingac
[originaltext]W:Well,isithardertobeacomedianorascientist?M:Ithink
[originaltext]W:Welcometoourprogram.Thisweek,wewouldliketotalkabout
[originaltext]M:[1-1]MaureenMcLaneisapoetandcritic.Afterherundergrad
[originaltext]Interviewer:Letmeturnitontothemanwhomayendupthewinn
随机试题
[originaltext]Asaresultofrisinguniversitycosts,manystudentsarefin
用Flash制作一个动画作品后,若要在编辑状态观察动画,使动画直接在舞台中播放,
乳癖类证鉴别
A. B. C. D.
2021年第一季度,全国集成电路进口单价约是出口单价的多少倍?A.1.4
小张同学期中考试的语文成绩为54分。按学校要求,试卷必须经家长签阅后送交班主任。
在火灾中,没有防火保护的受力钢构件极易受高温而发生变形,当温度升至300℃时,钢
A.木通 B.通草 C.大血藤 D.鸡血藤 E.钩藤属于五加科的是
患者,女,30岁,5个月前顺产一女婴,坚持母乳喂养,向药师咨询哺乳期安险用药问题
医学模式是A.人类对健康与疾病问题观察、处理的标准方法 B.人类对健康问题观察
最新回复
(
0
)