1、(完整版)2019大学英语四级阅读理解练习题(10)2019大学英语四级阅读理解练习题(10) 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
2、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 so
3、lution 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 diffic
4、ult 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 do
5、ne, 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 c
6、an 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 b
7、y 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
8、 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