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
2024-04-26
44
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 kilometres 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. There are two areas of radiation about 1,500 miles away from the earth. Neither of these forms of radiation are 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 armful 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.
Questions 23 to 25 are based on the passage you have just heard.
23. What forms of radiation are feared by astronauts?
24. What can we infer from the passage?
25. Why can’ t people on earth be harmed by radiation?
选项
A、Radiation from the sun.
B、Radiation from the Van Allen Belts.
C、Radiation from the Van Allen Belts and from the meteors.
D、Radiation from the sun and from the Van Allen Belts.
答案
D
解析
短文中间提到,There are two sorts of radiation mail must fear in space,即radiation from the sun和from…Van Allen Belts,由此可知,答案为D)。短文中虽提到meteors(流星),但其危害是being hit by meteors,并非流星发出的射线,故排除C);A)和B)表述不全面。
转载请注明原文地址:https://tihaiku.com/zcyy/3572527.html
相关试题推荐
[originaltext]M:Theelectionwillbeverycloseaccordingtothepolls.W:Rem
[originaltext]M:Theelectionwillbeverycloseaccordingtothepolls.W:Rem
[originaltext]M:Theelectionwillbeverycloseaccordingtothepolls.W:Rem
[originaltext]Manyfactssuggestthatchildrenareoverweightandthesitua
[originaltext]Manyfactssuggestthatchildrenareoverweightandthesitua
[originaltext]Inthislesson,IwanttotalkaboutthehistoryofTheWhite
[originaltext]Inthislesson,IwanttotalkaboutthehistoryofTheWhite
[originaltext]ZoeChamberswasasuccessfulPR(PublicRelations)consultant
[originaltext]ZoeChamberswasasuccessfulPR(PublicRelations)consultant
[originaltext]M:Iwasyoungoncemyself,youknow.Iknowwhatit’sliketobe
随机试题
Whentheenginewouldnotstart,themechanicinspectedallthepartstofindwh
[originaltext]Thetimeisfouro’clock.Therehasbeenaseriousaccide
Completethenotesbelow.WriteNOMORETHANTWOWORDSforeachanswer.JOBENOU
在我国,客户在期货公司开户时,须签字的文件包括()等。A、委托代理协议书B、期货交易风险说明书C、期货经纪合同D、买卖自负承诺书B,C在我国,客
在连续三年停止使用撤销复审案件中,复审商标核定使用的商品仅非医用营养品一项,该商
在杜邦财务分析体系中,假设其他情况相同,下列说法中错误的是()。A.权益
()不是证券经营机构及其工作人员在落实执行投资者适当性管理的过程中应当遵循的
某企业生产中合理安排计划,改进物料储存方法,加强物料管理,这是清洁管理途径中的(
总需求数量和社会整体物价水平之间呈现( )相关的关系;社会的总供给量和物价水平之
下列关于设计施工总承包合同的说法,正确的是( )。A.合同责任单一 B.有利
最新回复
(
0
)