首页
登录
职称英语
Every day of our lives we are in danger of instant death from small high-spe
Every day of our lives we are in danger of instant death from small high-spe
游客
2023-12-24
49
管理
问题
Every day of our lives we are in danger of instant death from small high-speed missiles from space—the lumps of rocky or metallic debris which continuously bombard the Earth. The chances of anyone actually being hit, however, are very low, although there are recorded instances of "stones from the sky" hurting people, and numerous accounts of damage to buildings and other objects. At night this extraterrestrial material can be seen as "fireballs" or "shooting stars", burning their way through our atmosphere. Most, on reaching our atmosphere, become completely vaporised.
The height above ground at which these objects become sufficiently heated to be visible is estimated to be about 60-100 miles. Meteorites that have fallen on buildings have sometimes ended their long lonely space voyage incongruously under beds, inside flower pots or even, in the case of one that landed on a hotel in North Wales, within a chamber pot. Before the era of space exploration it was confidently predicted that neither men nor space vehicles would survive for long outside the protective blanket of the Earth’s atmosphere. It was, thought that once in space they would be seriously damaged as a result of the incessant downpour of meteorites falling towards our planet at the rate of many millions every day. Even the first satellites showed that the danger from meteorites had been greatly overestimated by the pessimists, but although it has not happened yet, it is certain that one day a spacecraft will be badly damaged by a meteorite.
The greatest single potential danger to life on Earth undoubtedly comes from outside our planet. Collision with another astronomical body of any size or with a "black hole" could completely destroy the Earth almost instantly.
Near misses of bodies larger than or comparable in size to our own planet could be equally disastrous to mankind as they might still result in total or partial disruption. If the velocity of impact were high, collision with even quite small extraterrestrial bodies might cause catastrophic damage to the Earth’s atmosphere, oceans and outer crust and thus produce results inimical to life as we know it. The probability of collision with a large astronomical body from outside our Solar System is extremely low, possibly less than once in the lifetime of an average star. We know, however, that our galaxy contains great interstellar dust clouds and some astronomers have suggested that there might also be immense streams of meteorite matter in space that the Solar system may occasionally encounter. Even if we disregard this possibility, our own Solar system itself contains a great number of small astronomical bodies, such as the minor planets or asteroids and the comets, some with eccentric orbits that occasionally bring them close to the Earth’s path. [br] What is the greatest danger to life on Earth?
选项
A、Collision with small high-speed missiles.
B、Collision with an astronomical body.
C、Collision with stones from the sky.
D、Collision with spacecrafts.
答案
B
解析
这是道细节题。从文章第三段的“The greatest single potential danger to life on Earth undoubtedly comes from outside our planet.Collision with another astronomical body of any size or with a ’black hole’ could completely destroy the Earth almost instantly.”(对地球生活造成最大毁坏的潜在威胁毫无疑问来自星球之外。和任何大小的天文体或者黑洞发生碰撞都将立刻把我们的地球毁于一旦。)知道答案应该是第二个,和天文体相撞。
转载请注明原文地址:https://tihaiku.com/zcyy/3300822.html
相关试题推荐
Heremainedcalminthefaceoftheimpendingdanger.A、terrificB、trivialC、asto
Heremainedcalminthefaceoftheimpendingdanger.A、terrificB、trivialC、asto
Itisimpossibleforparentsto______theirchildrenfromeverydanger.A、protect
Heremainedcalminthefaceoftheimpendingdanger.A、terrificB、trivialC、asto
Itssuccesswasinstantaneous,thoughneitherthehostnorMr.Pepyscouldquite
Thereactionwasinstantandoverwhelming.Socialmediaexploded,radiophone-in
Thereactionwasinstantandoverwhelming.Socialmediaexploded,radiophone-in
Everydayofourlivesweareindangerofinstantdeathfromsmallhigh-spe
Everydayofourlivesweareindangerofinstantdeathfromsmallhigh-spe
Everydayofourlivesweareindangerofinstantdeathfromsmallhigh-spe
随机试题
Suchcrimesmaybesocomplexthatmonthsoryearsgobybeforeanyone______th
你的青春就是一场远行,一场离自己的童年,离自己的少年,越来越远的远行。你会发现这个世界跟你想象的一点都不一样,你甚至会觉得很孤独,你会受到很多的排挤。度假和
在第3-5腰椎高度的椎管内不含有:()A.尾神经根 B.骶神经根 C.
()是目前我国股权投资基金最主要的投资资金来源。A.工商企业 B.社会保障基
青蒿抗疟的有效成分是A.青蒿素B.青蒿内酯C.青蒿酸D.青蒿醇E.挥发油
直流系统充电装置型式应选用特高频开关电源模块型充电装置。
既能治疗湿热黄疸,又能治疗大便秘结的药物是A.大黄 B.蔊菜 C.马兜铃
视杆系统( )。A.对光敏感度高,有色觉,分辨力弱 B.对光敏感度低,有色觉
某男,65岁。久咳不已,短气乏力,痰多清稀,食纳减少,腹胀便溏,足面浮肿,苔白舌
A.异种抗原 B.同种异型抗原 C.自身抗原 D.异嗜性抗原 E.肿瘤相
最新回复
(
0
)