首页
登录
职称英语
If the population of the earth goes on increasing at its present rate, there
If the population of the earth goes on increasing at its present rate, there
游客
2024-01-17
15
管理
问题
If the population of the earth goes on increasing at its present rate, there will eventually not be enough resources left to keep our lives on the planet. By the middle of the 21st century, if present trends continue, we will have used up all the oil that drives our cars. Even if scientists develop new ways of feeding the human race, the crowded conditions on earth will make it necessary for us to look for open space somewhere else. But none of the other planets in our solar system are capable of supporting life at present. One possible solution to the problem, however, has recently been suggested by American scientist, Professor Carl Sagan.
Sagan believes that before the earth’s resources are completely used up it will be possible to change the atmosphere of Venus and so create a new world almost as large as earth itself. The difficulty is that Venus is much hotter than the earth and there is only a tiny amount of water there. Sagan proposes that algae(藻类)organisms that can live in extremely hot or cold atmospheres and at the same time produce oxygen, should be bred in condition similar to those on Venus. As soon as this has been done, the algae will be placed in small rockets. Spaceship will then fly to Venus and fire the rockets into the atmosphere. In a fairly short time, the algae will break down the carbon dioxide into oxygen and carbon.
When the algae have done their work, the atmosphere will become cooler, but before man ban set foot on Venus it will be necessary for the oxygen to produce rain. The surface of the planet will still be too hot for man to land on it but the rain will eventually fall and in a few years something like earth will be reproduced on Venus. [br] Man can land on Venus only when______.
选项
A、the algae have done their work
B、the atmosphere becomes cooler
C、there is oxygen
D、it rains there
答案
B
解析
此题问的是人类在什么情况下可以登上金星,属于细节事实题,正确答案可以在最后一段中找到。此段讲到了“当藻类植物发挥作用之后,大气层会冷却,但是在人类登陆之前,氧气要能够产生雨水,因为金星表面对于人类来说仍然过热,但是雨水降下后的几年,金星的整个环境就会变得与地球类似,所以可以推断人类只有在大气层冷却之后才能登上金星”。正确答案选择B。
转载请注明原文地址:https://tihaiku.com/zcyy/3370904.html
相关试题推荐
—WhatpresentshallwemakeSimonforhisbirthday?Whatkindofthingsdoeshe
Themainreasonforthepopulationgrowthisn’tsomuchariseinbirthrates__
Hefounditincreasinglydifficulttoread,______hiseyesightwasbeginningto
ThepopulationofChina______morethanonefifthofthetotalpopulationinthe
SpeakerA:Couldyougivemearidetotheconferencecenter?Mypresentationis
Thoughitismere1to3percentofthepopulation,theupperclasspossesse
Thoughitismere1to3percentofthepopulation,theupperclasspossesse
Aspopulationincreases,______.A、industrialoutputalsodoesB、asindustrialout
Increasingly,overthepasttenyears,people—especiallyyoungpeople—haveb
Increasingly,overthepasttenyears,people—especiallyyoungpeople—haveb
随机试题
IfNajibullahZaziiseverythingtheFBIsaysheis,thentheAfghan-bornDe
ThefamilyisthecenterofmosttraditionalAsians’lives.Manypeoplewor
Thispartistotestyourabilitytodopracticalwriting.Youarerequiredtow
造成牙体缺损的病因是()A.龋病 B.牙外伤 C.磨损 D.楔状缺损
经行小腹胀痛,行经后痛减者,多属()A.血虚 B.肾虚 C.寒凝
投资者预期股票价格上涨,可以通过(),构造牛市价差期权。 Ⅰ.购买较低执行价格
健脾丸与归脾汤均有的功效( )。A.温阳健脾 B.益气健脾 C.健脾止泻
甲对乙享有100万元债权,乙对丙享有100万元债权。现甲对乙的债权到期。乙对丙的
某软件开发企业为增值税一般纳税人,2021年4月销售自产软件产品取得不含税
下列农业组织中,其最大的特点是半官半民性质的是()。A.以色列莫沙夫合作社
最新回复
(
0
)