首页
登录
职称英语
[originaltext] Not long ago it was assumed that the dangers man would meet in
[originaltext] Not long ago it was assumed that the dangers man would meet in
游客
2024-06-14
37
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-caned Van Allen Belts. There are two areas of radiation about 1 500 miles away from the earth. Neither of these forms of radiation area 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.
选项
A、Radiation from the sun.
B、Radiation from the Van Allen Belts.
C、Radiation from the meteors.
D、Radiation from the Van Allen Belts and from the meteors.
答案
D
解析
What forms of radiation are feared by astronauts?
四个选项都提到了radiation,由此可以推测,本问题的考查内容可能与某种辐射有关。
文中提到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. 在外太空,宇航员必须提防的辐射有两种。一种是太阳辐射,一种是所谓的“Van Allen Belts”辐射。故正确答案为D)。
转载请注明原文地址:https://tihaiku.com/zcyy/3633458.html
相关试题推荐
[originaltext]Aworld-championbodybuilderhasnomoremusclesthandoesa
[originaltext]Aworld-championbodybuilderhasnomoremusclesthandoesa
[originaltext]Manyayoungpersontellsmehewantstobeawriter.Ialway
[originaltext]Manyayoungpersontellsmehewantstobeawriter.Ialway
[originaltext]Scientistssaysharkshavelivedintheworld’soceansformi
[originaltext]Scientistssaysharkshavelivedintheworld’soceansformi
[originaltext]Mostpeoplefeellonelysometimes.Butitusuallyonlylasts
[originaltext]Agoodmarriagemeansgrowingasacouplebutalsogrowingas
[originaltext]W:Hi,Steve!M:Hi,Jan.I’mplanningtogotoLondonbytrain.
[originaltext]W:Hi,Steve!M:Hi,Jan.I’mplanningtogotoLondonbytrain.
随机试题
Youwillhearanotherfiveshortpieces.Foreachpiecedecidewhatthespeaker
Facingtheboardofdirectors,hedidn’tdeny______breakingtheagreement.(2013
______,hecannowonlywatchitonTVathome.A、Obtainingnotaticketforthe
Thereisnodenyingthatourworldisbecomingmoreandmoredeveloped.Due
事故统计指标通常分为绝对指标和相对指标。下列生产事故统计指标中,属于相对指标的是
我国签证分为()。A.外交签证 B.公务签证 C.移民签证 D.礼遇签证
关于电子的量子数,下列()项可能存在。
分析人力资源费用预算中,要考虑的因素有()A.物价指数 B.工资指导线
期货交易所交易规则应当载明下列()事项。A.期货交易、结算和交割制度 B.风
腰痛多年,时轻时重,伴双下肢痛。10天前搬重物后腰腿痛加剧,并出现麻木与排尿困难
最新回复
(
0
)