题目内容：

Scientists are worried that an asteroid(小行星) will possibly hit the earth in 2036. If scientists are right, planet earth is 24 years away from a major disaster.

Scientists have been monitoring the progress of a 390-metre-wide asteroid ever since it was discovered last June. They have announced that it could hit the earth, causing huge damage, in 2036.

NASA estimates that the impact from the asteroid named after Apophis and ancient Egyptian demon(魔鬼) would release more than 100,000 times the energy released in the nuclear explosion over Hiroshima. Thousands of square kilometers would be directly affected by the explosion. The whole planet would see the effects of the dust released into the atmosphere.

This is the worst possible scenario(情景) of any asteroid in recorded history.

Having more than 20 years’ warning of possible impact might seem plenty of time. But scientists insist that there is actually very little time left to decide.

Luckily, however, they aren’t short on ideas for deflecting the asteroid. The favored method is also probably the easiest—throwing a spacecraft at the asteroid to change its direction. The European Space Agency plans to test this in the next decade.

One idea that seems to have no support from astronomers is the use of explosive, although this sounds more likely to the public or Hollywood producer.

At present, scientists are trying to make a better estimate of how much time we have, through more observations.

In spring of next year, there will be another chance for radar observation of Apophis. This will help astronomers calculate the orbits of the asteroid more accurately.

If, at that stage, they can’t rule out an impact with the earth in 2036, the next chance to make better observations will not be until 2016, then 2029.

“If we wait until 2029 and the worst—case scenario turns out to be true, it would seem unlikely that we’d be able to do anything about 2036,” warns Prof Fitzsimmons.

1.What does the underlined word “deflecting” most probably mean?

A．making it smaller.

B．observing it clearly enough.

C．dividing into pieces.

D．changing its direction.

2.According to the scientists’ observation, _______.

A．the asteroid named Apophis will explode in 2036.

B．the asteroid named Apophis might hit the earth in 2036.

C．the asteroid named Apophis is 24 years old.

D．there is plenty of time to decide the way we deal with the asteroid.

3.What is the impact from Apophis if it hits the earth?

A．It will damage Hiroshima.

B．Thousands of square kilometers would see the effects of the dust released into the atmosphere.

C．It might be the worst damage caused by asteroids in recorded history.

D．The whole planet would be directly affected by the explosion.

4.It can be inferred from the text that _____.

A．Hollywood producers will explode Apophis to avoid its hit.

B．There are only two chances for scientists to make better observations if they can’t grasp the chance next year.

C．NASA plans to throw a spacecraft at Apophis to change its direction.

D．It is supportive from astronauts that we explode the Apophis.