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
Uber在伦敦失去牌照了,彻底不能运营
The Things that Money Cant Buy 钱买不到的东西
德国养狗男子重病惨死,原因竟只是被狗舔过
国际英语资讯:Commentary: Washingtons egoistic double standard on human rights
国际英语资讯:Iraqi PM holds session to discuss resignation
被危险动物叮咬是什么感觉?《疼痛之王》告诉你
网恋渐成主流 “E时代新生儿”将迎大爆发
体坛英语资讯:Marathon novices Jepkosgei, Wacera seek to steal the thunder in New York
国内英语资讯:China suspends Hong Kong visits by U.S. military ships, aircraft, sanctions U.S. NGOs
体坛英语资讯:Halep rebounds to defeat Andreescu in WTA finals group stage
昨晚我看到了真爱
国际英语资讯:51 quake fatalities confirmed as rescue operations end in Albania
体坛英语资讯:Hamilton wins F1 Mexican GP but must wait for title win
国际英语资讯:One killed, 20 injured in traffic accident in Canada
体坛英语资讯:Granada go top as Sevilla, Atletico and Real Sociedad all pressure Barca
国外版“从前慢”:为了鼓励社交,冰岛周四没电视
亚马逊推出了一个大板子,功能:自动帮你剁手买买买
国内英语资讯:Chinese vice premier stresses all-out efforts in restoring hog production
国内英语资讯:China makes progress in AIDS prevention, treatment
美国82岁老太把28岁劫匪打到送医:我又老又孤单但很强
国际英语资讯:Iran starts candidate registration for parliamentary elections
体坛英语资讯:Preview: Barca and Real Madrid back in action in Spains Matchday 11
国际英语资讯:Libyas Tripoli intl airport to resume flights on Dec. 12
国内英语资讯:Chinas Hubei opens scenic high-speed railway
国内英语资讯:New govt team shows spirit of reform, innovation: Macaos fifth-term chief executive
体坛英语资讯:Analysis: Four things we learned in Spains Matchday 10
国内英语资讯:Giant pandas well adapting first winter on Qinghai Plateau
国内英语资讯:China launches weeklong Constitution publicity campaign
国内英语资讯:Xi stresses modernization of Chinas emergency management system, capability
2019年12月英语四级作文范文:卡奴
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |