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
40
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
以下不属于市场风险的是()。 A.利率风险 B.汇率风险 C.商品价
(2017年)根据《水利部关于调整水利工程建设项目施工准备开工条件的通知》(水建
期货公司金融期货结算业务资格分为()。
下列哪项不是早期食管癌的临床表现
某女性患者,咳嗽、右侧胸痛、气促3个月,诊断右侧大量胸腔积液。该患者多采取何种体位?()A.自主体位B.被动体位C.患侧卧位D.端坐呼吸
从所给的四个选项中,选择最合适的一个填人问号处,使之呈现一定的规律性:
关于断肢再植原则,下列哪项是错误的A.首先进行彻底的清创B.需要时可将骨骼短缩后重建C.肌腱常作二期缝接D.主要的动、静脉均应吻合E.神经应一期修复
A建筑公司承担某土方开挖工程。工程于1月开工,根据进度安排同年2月份计划完成土方量4000立方米,计划单价为80元/立方米。时至同年2月底,实际完成工程量...
个案研究的优点表现在()。A.了解研究对象各方面的状况,进而对其有全面和深入的认识B.有助于提出有效和具体的处理办法或解题方案C.有助于澄清概念和确定变量
社区工作者小莉刚到深圳大棚社区,她想了解社区所拥有的资源,以方便以后开展社区活动,在小莉挖掘社区资源的过程中,应重视()。A:培养社区骨干B:招募和组织社区志