阅读理解 By now, a rocket will have set off

问题：

阅读理解

     By now, a rocket will have set off on its 35-million-mile trip to Mars and scientists must be waiting for

the results.

     The rocket will be travelling for six months before it reaches the planet. It contains a number of

scientific instruments, including a television camera. Any picture that is taken will have to travel for three

minutes before they reach the earth. If the pictures are successful, they may solve a number of problems

about Mars and provide information about the markings on its surface which, nearly 100 years ago, the

astronomer (天文学家), Schiaparelli, thought to be canals.

     It will be a long time before any landing on Mars can be tried. This will only be possible when scientists have learned a lot more about the atmosphere that surrounds the planet. If a satellite can one day be put

into orbit round Mars, scientists will be able to find out a great deal. An interesting suggestion for

measuring the atmosphere around Mars has been made. A rubber ball having a radio transmitter(无线电发报机) could be dropped from a satellite so that it would fall towards the surface of the planet. The radio would tell the rate(速度) at which the ball was slowed down and scientists would be able to calculate how dense the atmosphere is. It may even be possible to drop scientific instruments on to the planet's surface. Only when a great deal more information has been got, will it be possible to plan a manned (载人的) trip

to Mars.

1. The first paragraph tells us _______ .

A. Mars is too far away for people to land on

B. it will take the rocket half a year to reach Mars

C. Mars is 53 million miles away from the earth

D. scientists have well known about the surface of Mars

2. The pictures taken by a television camera _______ .

A. will have to be put into the scientific instruments

B. will prove what Schiaparelli thought about is false

C. will be received by the earth in three minutes' time

D. can help people do much less research work

3. It seems that _______ might prevent scientists from landing on Mars.

A. the atmosphere round the planet

B. the orbit round the planet

C. having little information

D. the markings on the planet's surface

4. Having successfully dropped the rubber ball, scientists would be able to calculate how dense the atmosphere is by _______.

A. slowing the ball down at a speed which could be measured

B. dropping another ball with scientific instruments on to the surface

C. putting down the ball towards the planet's surface

D. measuring the speed at which the ball was falling

5. It is not until _______ that people can think of a plan to make a trip to Mars.

A. they have got enough scientific instruments

B. they have a lot more information

C. dense enough atmosphere is found around the planet

D. a reasonable suggestion has been made