四、完形填空。〔人与自然——宇宙探索〕
Dear Mary,
Thanks for your letter! You are so 1 that you are going to travel to Mars. I think you have read books 2 Mars. But there are a lot of things you won't learn just by 3. You had better practise much.
The cheapest round trip costs about 30,000. The 4 depends on how far Mars is from the Earth. You may be 5 to know that the shortest trip costs the most! On short trips you experience great changes of 6 as you jump from one orbit (轨道) to another. And in space, speed, rather than distance, costs money. You won't be able to 7 many things with you. But it really doesn't 8, because you can buy what you need when you 9 Mars.
Remember to take a 10. You can take some wonderful photos 11 you leave the Earth and as you come near Mars. And you can 12 the good camera on Mars at a higher price. Your 13 will probably leave from a high mountaintop in New Guinea (新几内亚). Where is it? It's on the equator (赤道). A spaceship 14 from there gets a speed boost of the Earth's spin.
15 a great and wonderful trip! I hope to hear from you soon.
Yours,
Helen
1. A. polite
B. friendly
C. clever
D. lucky
2. A. with
B. out
C. about
D. in
3. A. speaking
B. reading
C. listening
D. watching
4. A. time
B. weather
C. trip
D. cost
5. A. happy
B. satisfied
C. surprised
D. worried
6. A. power
B. speed
C. directions
D. clothes
7. A. buy
B. borrow
C. carry
D. set
8. A. work
B. mind
C. matter
D. care
9. A. arrive
B. reach
C. leave
D. come
10. A. radio
B. TV
C. camera
D. computer
11. A. if
B. before
C. since
D. when
12. A. borrow
B. lend
C. sell
D. show
13. A. train
B. spaceship
C. car
D. plane
14. A. showing off
B. getting to
C. taking off
D. getting on
15. A. Need
B. Have
C. Look
D. Borrow

1~5. DCBDC 6~10. BCCBC 11~15. DCBCB