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
2024-03-09
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、Traffic accidents.
B、Radiation.
C、Train travel.
D、Air crash.
答案
B
解析
原文提及“不久前人们认为在太空中会遭遇到严重的威胁,主要有辐射和流星撞击”。故B正确。
转载请注明原文地址:https://tihaiku.com/zcyy/3517845.html
相关试题推荐
[originaltext]Insectsanddiseasesthatattackfoodcropsaremovingasrise
[originaltext]StudentsinAmericanschoolslearnfromanearlyagetogivep
[originaltext]Thefirstyearofcollegeisoneofthebestandthemostinte
[originaltext]Thefirstyearofcollegeisoneofthebestandthemostinte
[originaltext]Thefirstyearofcollegeisoneofthebestandthemostinte
[originaltext](13)Thisisadiscussioncoursewhereyouractiveattendance
[originaltext]Hungryforthebrighteststudents,manyofthecountry’sstron
[originaltext]Hungryforthebrighteststudents,manyofthecountry’sstron
[originaltext]Hungryforthebrighteststudents,manyofthecountry’sstron
[originaltext]M:Asweprobablyknow,logstructuresaregainingpopularity.We
随机试题
Whenmymother’shealthwasfailing,Iwasthe"bad"sisterwholivedfaraw
Inthissection,youaregoingtoreadapassagewithtenstatementsattachedto
A、Theycanbetrainedtodeliverthings.B、Theycanbeputtouseasguidedogs.
病变位于肌肉,病变组织出现嗜碱性巨细胞,肌肉呈棋盘状的是:()A.增生性筋膜
某工程项目,承包工程合同总额为4000万元,工程预付款总额为500万元,主要材料
与银汞合金相比,后牙复合树脂牙体修复的缺点是A.美观性能差 B.牙体预备保守
下列资产类别中收益期望值从低到高的顺序是()。 Ⅰ.货币市场基金 Ⅱ.债券基
下列说法符合《上市公司证券发行管理办法》公开发行新股规定的是( )。 Ⅰ公司
刘老师家庭负担重,老人要看病,孩子要读书,于是用假名在培训机构上课,挣钱补贴生活
下列自动化仪表线路的敷设,正确的有( )。 A.敷设在高温管道上方200mm
最新回复
(
0
)