六级冲刺练习阅读34

　　When numbers rise the 14 mouths must be fed. New lands must be I bought under cultivation, or land already farmed made to 15 larger crops. In some areas the accessible land is largely so intensively 16 that it will be difficult to make it provide more food. In some areas the population is so dense that the land is parceled out in units too 17 to allow for much improvement in farming methods. Were a larger part of this farming population drawn off into industrial occupations, the land might be farmed much more productively by modern methods.

　　There is now a race for science, technology, and industry to keep the 18 of food rising faster than the number of people to be fed. New strains of crops are being developed which will thrive in 19 climates; irrigation and dry-farming methods bring poor lands under the plough, dams hold back the waters of great rivers to 20 water for the fields in all seasons and to provide electric power for new industries; industrial chemistry provides fertilizers to suit particular soils; aero planes spray crops to destroy insects and many plant diseases.

　　A. ensure B. violently C. alter D. harmful E. cultivated F. unique G. transplanted H. yield I. consequence J. output K. extra L. steadily M. tiny N. unfavorable O. produce

　　II. C 12. I 13. L 14. K 15. H 16. E 17. M 18. J 19. N 20. A