Can you imagine living and working in a one-man submarine (潜水艇)? Scientists believe that 1C one-man submarines will be as 2B as automobiles are today.
First, 3B , the human problems involved 4B the ocean living will need to be studied in 5C , and scientists have already begun to work in 6C fields as marine biology, ocean currents, and ocean-bottom geology.
7B studying ocean plants and animals, science may find a(n) 8C for some of our most serious diseases. And we may learn to use 9D plants to increase our world food supply 10D .
11C new tools and machines, mining engineers may make 12D possible to get valuable 13B from the ocean. 14C , ocean minerals renew themselves, 15A land minerals, which are gone forever 16C taken out of the earth.
Above all, the sea has 17A of space, not 18C for floating communities and parks, but also for 19B supplies and for underwater travels.
Indeed, ocean living will help man in more than physic ways. In the freedom and beauty of the deep sea, man may 20B new sources of joy.
1. A. sometimes B. somehow C. someday D. somewhat
2. A. much B. many C. well D. fine
3. A. however B. therefore C. though D. of all
4. A. on B. in C. at D. for
5. A. fact B. general C. detail D. short
6. A. the B. same C. such D. other
7. A. With B. By C. On D. For
8. A. key B. way C. cure D. answer
9. A. better B. cheaper C. water D. sea
10. A. yet B. also C. too D. as well
11. A. Through B. To C. With D. In
12. A. something B. them C. things D. it
13. A. foods B. metals C. plants D. animals
14. A. Possibly B. Hopefully C. Fortunately D. Naturally
15. A. unlike B. as C. besides D. dislike
16. A. while B. before C. once D. when
17. A. plenty B. vast C. enough D. many
18. A. really B. yet C. only D. simply
19. A. maintaining B. storing C. protecting D. preventing
20. A. take B. find C. feel D. make