日日人人_亚洲美女在线视频_av手机在线播放_国产大片aaa_欧美中文日韩_午夜理伦三级

It will take the man half an hour _____ the work.

       A. finish   B. finishing    C. to finish    D. finishes

 It will take the workers half a year _______ building the bridge.

A. finish   B. finishing    C. to finish    D. finishes

Astronauts have already visited the moon and lived on space stations. They' ve never been to another planet, but they might visit Mars soon. The astronauts will spend about six months traveling to the planet, then about two years on the planet and about six months traveling back to the earth. They' ll be away from the earth for about three years, so they' 11 need a lot of food !

It' s very expensive to take food into space. It costs about 120,000 dollars to carry something that weighs one kilogram. So an apple on Mars could cost 20,000 dollars! Of course, they will need to take quite a lot of food with them to feed the astronauts for three years. This amount of fresh food can not stay fresh, and is very expensive to take, so they need to find food that is not very heavy.     

At the moment, astronauts on space stations eat dried food. It's very light, so it doesn't cost a lot of money to carry it into space. But astronauts stay healthier and happier if they eat fresh food. In the future, astronauts on Mars may grow vegetables like lettuce, spinach and carrots.

Astronauts on Mars will probably have special machines. They' ll use these machines to change beans into foods that taste like meat or cheese because it won' t be possible to keep animals in space.

1. The astronauts plan to go to           next.               

A. the earth         B. the moon      C. Mars              D. space

2. Why do the astronauts have to eat dried food?

A. Because it is safe.            B. Because it makes them happy.    

C. Because it is cheap to buy.     D. Because it is cheap to carry.     

3. What may astronauts do in the future?

A. Take enough fresh food for their journey.     

B. Grow some fresh vegetables on Mars.

    C. Keep animals in space.

    D. Grow food on their space stations.

4. Which of the following is TRUE according to the passage?    

A. It will take the astronauts six. months to get to a planet.    

B. If we take two kilograms of apples into space, it could cost 40,000 dollars.

C. Dried food is as healthy as fresh food for astronauts in space.

    D. Astronauts will get foods that taste like meat or cheese from beans on Mars.

5. The best tide for this passage is

    A. Food in Space                      B. An Important Planet

    C. Vegetables in Space                 D. Astronauts in the Future