228. We made plans for a visit but _____ difficulties with the car prevented it.

　A. consequent B. subordinate C. substantial D. subsequent

227. He didn't _____ what I read because his mind was on something else.

　A. hold on B. catch on C. take in D. get over

226. Scientists have to work hard to keep _____ with modern discoveries and developments.

　A. company B. track C. touch D. pace

225. She _____ the temptation to buy a coat she could not afford.

　tradicted D.resisted

224. He put in a special _____ for an extra day's holiday so that he could attend his daughter's wedding.

　A. request B. demand C. inquiry D. proposal

223. It was decided to _____ the search when there was no hope of finding the missing girl alive.

　A. call off B. take up C. keep off D. ring up

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