首页
财务会计
医药卫生
金融经济
考公考编
外语考试
学历提升
职称考试
建筑工程
IT考试
其他
登录
职称考试
Passage 2 If the population of the earth goes on increasing at its present r...
Passage 2 If the population of the earth goes on increasing at its present r...
admin
2020-12-24
17
问题
Passage 2
If the population of the earth goes on increasing at its present rate, there will eventually not be enough resources left to sustain life 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, for example. 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 an American scientist, Professor Carl Sagan.
Sagan believes that before the earth's resources are completely exhausted 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 organisms, which can live in extremely hot or cold atmospheres and at the same time produce oxygen, should be bred in conditions similar to those on Venus. As soon as this has been done, the algae will be placed in small rockets. Spaceships 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 can 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 men to land on it but the rain will eventually fall and in a few years something like earth will be reproduced on Venus.
Man can eventually land on Venus only when__________.
查看材料
选项
A.the algae have done their work
B.the atmosphere becomes cooler
C.there is oxygen
D.it rains there
答案
D
解析
由最后一段中“before man can set foot on Venus it will be necessary for the oxygen to produce rain”可知,只有金星上有降雨,人类才最终有可能在上面着陆。所以正确答案为D。
转载请注明原文地址:https://ti.zuoweng.com/ti/yHT8KKKQ
相关试题推荐
Passage2 Americanstodaydon′tplaceaveryhighvalueonintellect.Ourhe...
Passage2 Americansdon’tliketolosewars.Ofcourse,alotdependsonhowy...
Passage2 Americansdon’tliketolosewars.Ofcourse,alotdependsonhowy...
Passage2 Americansdon’tliketolosewars.Ofcourse,alotdependsonhowy...
Passage2 Americansdon’tliketolosewars.Ofcourse,alotdependsonhowy...
Passage2 Ofallthecomponentsofagoodnight′ssleep,dreamsseemtobe...
Passage2 Ofallthecomponentsofagoodnight′ssleep,dreamsseemtobe...
Passage2 ForcenturiesinSpainandLatinAmerica,headinghomeforluncha...
Passage2 ForcenturiesinSpainandLatinAmerica,headinghomeforluncha...
Passage2 ForcenturiesinSpainandLatinAmerica,headinghomeforluncha...
随机试题
关于胃下垂,描述错误的是 A.指胃小弯角切迹低于髂嵴连线以下,并有十二指肠壶腹
1983年国务院决定中国人民银行专门行使国家中央人民银行职能,其主要职责不包括(
对于市政管线工程的审核,应当依据《城市工程管线综合规划规范》(GB50289-
某客户持有一份九月份小麦看涨期权,期权费为200元,则该客户的利润区间为()。
教材的主体部分是()。 A.讲授提纲和讲义 B.教科书和参考书 C.教科书
上市公司控股股东对上市公司和社会公众股东负有诚信义务,不得有下列()行为。A、违规占用上市公司资金B、违规为关联方提供担保C、提名董事、监事候选
铜芯导线或电缆的截面面积在1区为()mm2以上,2区为()mm2以上。A.1.5,2.5B.2.5,1.5C.2,1.5D.1.5,2
根据《标准设计施工总承包合同》,关于工程分包的说法,正确的是()A:承包人不得将其承包的工程分包给第三人B:投票文件中已说明的分包,合同履行时还需再征得发包人
某家电生产企业围绕家电市场,生产电视机、洗衣机、电冰箱、空调等系列家电产品。该企业采取的是()。A.水平多元化B.垂直多元化C.同心型多元化D.非相关
没有语言处理程序的支持,用户编写的应用软件也可以被计算机接受和执行。()