15. The European Union countries were once worried that they would not have _____      supplies of petroleum.
　　A. proficient      B. efficient
　　C. potential      D. sufficient
　　16. Britain has the highest _____ of road traffic in the world-over 60 cars for every mile of road.
　　A. popularity      B. density
　　C. intensity      D. prosperity
　　17. They are trying to _____ the waste discharged by the factory for profit.
　　A. expose    B. exhaust   C. exhibit   D. exploit
　　18. All their attempts to  _____ the child from the burning building were in vain.
　　A. regain   B. recover  C. rescue   D. reserve
　　19. Some plants are very   _____ to light; they prefer the shade.
　　A. sensible    B. flexible  C. objective   D. sensitive
　　20. The ______ at the military academy is so rigid that students can hardly bear it.
　　A. convention   B. confinement C. principle   D. discipline
　　21. It was the first time that such a ______had to be taken at a British nuclear power station.
　　A. presentation   B. precaution  C. preparation   D. prediction
　　22. ______ that he wasn't happy with the arrangements, I tried to book a different hotel.
　　A. Perceiving   B. Penetrating  C. Puzzling   D. Preserving
　　23. You should try to ______ your ambition and be more realistic.
　　A. reserve   B. restrain  C. retain   D. replace
　　24. He never arrives on time and my _______ is that he feels the meetings are useless.
　　A. preference B. conference C. inference D. reference
　　25. As one of the world's highest paid models, she had her face_______. for five million dollars
　　A. deposited B. assured C. measured D. insured
　　26. Because of his excellent administration , people lived in peace and _____ and all previously neglected matters were taken care of .
　　A. conviction B. contest   C. consent D. content
　　27. Showing some sense of humor can be a(n) _______ way to deal with some stressful situation .
　　A. effective B. efficient C. favorable D. favorite
　　28.The mayor ______ the police officer a medal of honor for his heroic deed in rescuing the earthquake victims.
　　A. rewarded B. awarded C. credited D. prized