一、根据句意，用括号中所给单词的适当形式填空
1. Each child needs to take __________ (dry) food and water for the trip.
2. A tent and a __________ (sleep) bag are necessary when you have to camp outside.
3. —What are you thinking about?
—I am thinking about __________ (travel) into space.
4. We need to wear special boots to make us heavier because there is __________ (little) gravity on Mars than on the Earth.
5. Life on Mars would be very interesting and there would be no __________ (pollute) there.

二、从方框中选择适当的单词和词组填空

Andy: Have you ever thought of living on Mars, Kitty?
Kitty: Yes, but I wonder what it would be like to live on Mars.
Andy: It’s much colder at night on Mars than on the Earth. We might need special
(1) __________ and (2) __________ before we could build houses on Mars.
Kitty: I hear the low gravity on Mars might be a problem, right?
Andy: Yes. We’d probably need to wear (3) __________ so that we could walk on Mars.
Kitty: What would we eat on Mars?
Andy: Scientists are not sure whether plants could grow there. Maybe we would have to eat
(4) __________.
Kitty: Oh, that’s terrible! Would we be dressed like an astronaut?
Andy: Sure. We might need to wear a(n) (5) __________ and carry a(n) (6) __________ on our back. They allow us to breathe on Mars.
Kitty: Sounds cool! Could we keep in touch with our family members and friends on the Earth?
Andy: I think a special (7) __________ could connect us with people back on the Earth.
Kitty: We might also need a(n) (8) __________ to provide enough energy.
Andy: I agree.