222. The Prime Minister refused to comment on the rumor that he had planned to _____.

　A. discharge B. dismiss C. resign D. resume

221. Professor Jordon is well known for his _____ into the habits of the common housefly.

　A. examination B. introduction C. research D. expression

220. I support your decision, but I should also make it clear that I am not going to be _____ to it.

　A. connected B. fastened C. bound D. stuck

219. John _____ knowledge of radio just by staying around the radio station.

　A. caught on B. worked up C. took up D. picked up

218. In spite of the thunderstorm, the children slept _____ all night.

　A. densely B. soundly C. loudly D. noisily

217. They did not find _____ to prepare for the worst conditions they might meet.

　A. worth their while B. it worthwhile C. it worth D. it worthy

216. The microphone enabled them to keep in touch, in other words, it made it _____ for them to contact each other.

　A. likely B. capable C. possible D. probable

215. She is making herself ill with _____ over her son's future.

　A. trouble B. annoyance C. disgust D. worry

214. When products made in factories _____, they are thrown away as garbage.

　A. come to an end B. are put to use C. are used up D. wear out

213. I _____ her not to walk on the thin ice but she would not listen to me.

　A. warned B. persuaded C. suggested D. noticed