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 lus 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 earths resources are compleetely exhausted it will be possible to change the atmophere of Venus and so create a new world almost as large as earth itself. The difficult is that Venus is much hotter than the earth and there is only a tiny amount of water there.
Sagan proposes that algae 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 alge will break down the carbon dioxide into oxygen and carbon.
When the algae have done theri work, the atmosphere will become cooler,but befor man can set foot on Venus it will be neccessary 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.
1.Inte long run, the most insoluble problem caused by population growth on earth will probably be the lack of ______.
a.food
b.oil
c.space
d.resources
2.Carl Sagan believes that Venus might be colonized from earth because _____
a.it might be possible to change its atmosphere
b.its atmosphere is the same as the earths
c.there is a good supply of water on Venus
d.the days on Venus are long enough
3.On Venus there is a lot of ________.
a.water
b.carbon dioxide
c.carbon monoxide
d.oxygen
4.Algae are plants that can____.
a.live in very hot temperatures
b.live in very cold temperatures
c.manufacture oxygen
d.all of the above
5. Man can land on Venus only when_______.
a.the algae have done their work
b.the atmosphere becomes cooler
c.thereis oxygen
d.it rains there
答案:cabdd
杨澜为李天一喊冤引争议
英语话剧剧本:三只小猪
“房媳”“房姐”仍在调查中
充分利用每一份资源 优化小学英语课堂教学
《What’s the matter?》、《Unit 2 My family》教后随笔--情趣教学合理利用
浅谈口语表达能力的培养
英语小剧本 Fox狐狸
5人搞笑英语剧本Today’s Yang bailao and Huang Shiren
小学英语《who is hungry 》课后随笔
三个人英语短剧本At the hotel
网曝李双江之子已取保候审回家
2A Unit6 教学随笔
北大保安与学生比苦读,英语四级是目标
两淘宝店主因海外代购偷税获刑
心痛学生的“不懂”
浅谈农村小学英语兴趣教学
浅谈新课程改革下小学生学习英语兴趣的培养
英文短剧本 梦想不会成真May Dream Won't Come Ture
“树洞画女孩”爆红
英语四级607高分经验
浅谈游戏在小学英语教学中的应用
9月英语教学随笔
英语剧本:去动物园
浅谈中职英语情景任务教学法
聋人大学生拿下英语四级 毕业后想做特教老师
赵本山否认操盘铁岭地块
童话英文短剧本:灰姑娘和眼睛蛇
不做差生的后娘
小学五年级英语教学论文
三人英语话剧剧本《新梁祝外传》现代版
不限 |