第16题 Many countries face some serious problems of land use, __ result from population growth and the demands of modem technological living.

　　A.which most

　　B.most of which

　　C.most which

　　D.of most which

　　【正确答案】：B

　　试题解析：这是由which引导的非限制性定语从句。

　　第17题 Our boss told me my plan was still __ discussion.

　　A.in

　　B. under

　　C. of

　　D. with

　　【正确答案】：B

　　试题解析：under discussion表示“在讨论中”，类似的还有under consideration(在考虑中)等。

　　第18题 Tom looks so pale today.He __ ill.

　　A.must be

　　B.had to be

　　C.should be

　　D.shall be

　　【正确答案】：A

　　试题解析：情态动词must表示推测。

　　第19题 He said he __ the next day.

　　A.will come back

　　B.come back

　　C.would come back

　　D.came back

　　【正确答案】：C

　　试题解析：主句谓语动词是过去时态，从句的时态应与主句一致。而从句中表示的是过去的将来，所以从句中的谓语动词应用过去将来时。

　　第20题 George did __ than anyone else.

　　A.much work

　　B.more work

　　C.work much

　　D.work more

　　【正确答案】：B