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
2023-08-18
51
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/2935668.html
相关试题推荐
[originaltext]Ifyou’recarefulenough,you’llfindthatitiscommonnowad
[originaltext]Ifyou’recarefulenough,you’llfindthatitiscommonnowad
[originaltext]InBritainthebiggestnumberofworkingforeignerscomesfro
[originaltext]Peter:(19)ThelawontaxisisveryinterestingandIknowinLon
[originaltext]Ababyspendsthefirstyearoflifelearningtolisten.(9)A
[originaltext]Ababyspendsthefirstyearoflifelearningtolisten.(9)A
[originaltext]Ababyspendsthefirstyearoflifelearningtolisten.(9)A
[originaltext]Ababyspendsthefirstyearoflifelearningtolisten.(9)A
[originaltext]W:Hi,Scott,haveyouheardaboutDianarecently?M:No,Ihave
[originaltext]W:Hi,Scott,haveyouheardaboutDianarecently?M:No,Ihave
随机试题
Despitetheirspartan,isolatedlifestyle,therearenostoriesofwomenbeingr
Whatisthemaintopicoftheconversation?[originaltext]M:I’mreallyshocked
Whoseworkswouldyoumostprobablychoosetoreadifyouwereinterestedinsat
“开学了,我们购置了笔、墨、纸、书等文具。”这句话所犯的逻辑错误是( )。A.
2014年末,表中所列超大城市常住人口同比增量占全国人口同比增量的()
按照我国《建筑工程施工质量验收统一标准》(GB50300-2013)检验批质量验
目前药材调剂最常用的计量工具是A:分厘戥B:盘称C:台秤D:天平E:戥称
存款人办理日常转账结算和现金收付的账户是()。A.基本存款账户 B.一
采用综合评估法对设计投标文件进行详细评审时的内容包括()。A.资信业绩评审 B
先在龙口建造浮桥或栈桥,由自卸汽车或其他运输工具运来抛投料,沿龙口前沿投抛的截流
最新回复
(
0
)