Unless we spend money to spot and prevent asteroids now, one might crash into Earth and destroy life as we know it, say some scientists.
Asteroids are bigger versions of the meteoroids that race across the night sky. Most orbit the sun far from Earth and dont threaten us. But there are also thousands of asteroids whose orbits put them on a collision course with Earth.
Buy $50 million worth of new telescopes right now. Then spend $10 million a year for the next 25 years to locate most of the space rocks. By the time we spot a fatal one, the scientists say, well have a way to change its course.
Some scientists favor pushing asteroids off course with nuclear weapons. But the cost wouldnt be cheap.
Is it worth it?Two things experts consider when judging any risk re:1)How likely the event is;and 2)How bad the consequences if the event occurs. Experts think an asteroid big enough to destroy lots of life might strike Earth once every 500, 000 years. Sounds pretty rarebut if one did fall, it would be the end of the world. If we dont take care of these big asteroids, theyll take care of us, says one scientist. Its that simple.
The cure, though, might be worse than the disease. Do we really want fleets of nuclear weapons sitting around on Earth?The world has less to fear from doomsday rocks than from a great nuclear fleet set against them, said a New York Times article.
21.What does the passage say about asteroids and meteoroids?
A) They are heavenly bodies different in composition.
B) They are heavenly bodies similar in nature.
C) There are more asteroids than meteoroids.
D) Asteroids are more mysterious than meteoroids.
22.What do scientists say about the collision of an asteroid with Earth?
A) It is very unlikely but the danger exists.
B) Such a collision might occur once every 25 years.
C) Collisions of smaller asteroids with Earth occur more often than expected.
D) Its still too early to say whether such a collision might occur.
23.What do people think of the suggestion of using nuclear weapons to alter the courses of asteroids?
A) It sounds practical but it may not solve the problem.
B) It may create more problems than it might solve.
C) It is a waste of money because a collision of asteroids with Earth is very unlikely.
D) Further research should be done before it is proved applicable.
24.We can conclude from the passage that ________.
A) while pushing asteroids off course nuclear weapons would destroy the world
B) asteroids racing across the night sky are likely to hit Earth in the near future
C) the worry about asteroids can be left to future generations since it is unlikely to happen in our lifetime
D) workable solutions still have to be found to prevent a collision of asteroids with Earth
25.Which of the following best describes the authors tone in this passage?
A) Optimistic.
B) Critical.
C) Objective.
D) Arbitrary.
答案:21.B 22.A 23.B 24.D 25.C
2014英语四级听力练习慢速3.18(1)
2014英语四级听力练习慢速(10)
2014英语四级听力练习慢速3.22(2)
2014英语四级听力场景词汇机场场景相关词汇
英语四级听力常考场景词汇疾病场景
2014英语四级听力练习慢速3.21(3)
英语四级听力备考方法
2014英语四级听力练习慢速3.18(2)
2014英语四级听力练习慢速3.22(1)
2014英语四级听力场景词汇工作词汇
2014英语四级听力练习慢速(6)
2014英语四级听力练习慢速3.18(3)
2014英语四级听力场景词汇娱乐词汇
2014英语四级听力场景词汇电话场景
2014英语四级听力场景词汇购物场景相关词汇
2014英语四级听力练习慢速3.21(2)
英语四级听力考前最后冲刺指南
2014英语四级听力场景词汇居住场景相关词汇
2014英语四级听力练习慢速3.15(1)
2014英语四级听力场景学习场景复习指导
2014英语四级听力练习慢速3.17(1)
2014英语四级听力练习慢速3.14(2)
2014大学英语四级考试听力笔记讲义(2)
2014英语四级听力练习慢速(3.13)
2014英语四级听力练习慢速3.20(2)
2014英语四级听力练习慢速3.16(1)
英语四级听力场景词汇公司场景
2014英语四级听力练习慢速3.17(2)
2014大学英语四级考试听力笔记讲义(3)
2014英语四级听力练习慢速3.21(1)
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |