192. Mary had taken _____ to see that her guests had everything that they could possibly want.

　A. efforts B. pains C. attempts D. endeavors

191. It isn't so much whether he works hard; the question is whether he works _____.

　A. above all B. in all C. at all D. after all

190. Expected noises are usually more _____ than unexpected ones of the like magnitude.

　A. manageable B. controllable C. tolerable D. perceivable

189. Experts say walking is one of the best ways for a person to _____ healthy.

　A. preserve B. stay C. maintain D. reserve

188. Jack almost fell off the cliff, but managed to _____ until help came.

　A. keep on B. catch on C. count on D. hang on

187. The storm sweeping over this area now is sure to cause _____ of vegetables in the coming days.

　A. rarity B. scarcity C. invalidity D. variety

186. Don't _____ the news to the public until we give you the go-ahead (许可，准许).

　A. release B. discard C. relieve D. retain

185. If you _____ your demand, then maybe you will have more chance of getting what you want.

　A. conduct B. dismiss C. grant D. moderate

184. His _____of the aeroplane was correct in every detail and could really fly.

　A. shape B. pattern C. design D. model

183. The open university was started in order to help those who _____ having a university education when they were young.

　A. stopped B. failed C. missed D. ceased