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
76
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
Janehadpromisedtogivemeatimetablefortomorrow.Shefailed,______.A、eithe
[originaltext]MostfarmersinCambodiagrowrice.Manyalsomaygrowcassav
压实度是检验路基路面施工质量的重要指标,试根据灌砂法测定压实度试验方法的有关规定
依据《涉外调查管理办法》,经批准进行的涉外社会调查,应当在调查问卷、表格或者访谈
结核性腹膜炎腹腔积液性质最常见的是A.血性 B.介于渗出液与漏出液之间 C.
十八届三中全会明确提出要维护宪法法律权威宪法是保证党和国家兴旺发达、长治久安的根
有关药品不良反应报告,下列说法中不正确的是A.药品生产经营企业和医疗预防保健机构
(2020年真题)如果实际利率为10%,通货膨胀率为2%,则名义利率为()。A.
某工程,监理单位承担了施工招标代理和施工监理任务。工程实施过程中发生如下事件:
急性淋病的首选治疗药物是A.壮观霉素 B.红霉素 C.青霉素 D.甲硝唑
最新回复
(
0
)