阅读理解。 Man has been to the moon.  It was been the first step to the future travels  in space. T he moon is much nearer to the earth than all the planets. Venus, the nearest planet to the earth is millions of kilometers away! Traveling  to the planets will be  man's  next step.   It will be more difficult than traveling  to  the moon  and certainly more exciting. In 1997, an American spaceship reached Mars, the second nearest planet from the earth. A wonderful robot slowly  walked  on the planet and worked hard.   It sent a lot of information back to the earth.  The most exciting piece was that there used to be a lot of water on Mars.  The American  scientists asked,  'Is there any life on Mars?' Unluckily, no life was found there, but American scientists do not lose heart. Russian spaceships have found that it is so hot on Venus that there must be no life there. Spaceship  of  the future will  be bigger and 'faster.  They will be able to carry people for travels to the moon or other planets. Man may in  the  future find planets l ike the earth and make them home.   But there is still a long,  long way to go. Man should learn to know that the earth will be his only home for a long time and begin to love and take good care of it. 1. The first step to the future travels in space is the . A. traveling to Mars B. traveling to the moon C. traveling to Venus D. traveling to the sun 2. The nearest planet to the earth is . A. Venus B. Mars C. the moon D. the sun 3. The American scientists find living things on Mars. A. believe they can B. are sure to C. try to D. are certain to 4. There must be no life on Venus because . A. there is little air B. it is too cold C. there is no water D. it is too hot 5. It will be possible for people to travel to the moon or other planets in the future because spaceship ____________. A. will be bigger B. will be faster C. will be comfortable D. Both A and B