12.Some metals are better conductors of electricity than oth

12.Some metals are better conductors of electricity than others,______ means that the former have atoms containing more free electrons than latter.
A.that B.this C.which D.it
13.If the earth suddenly ______ spinning,we would all fly off it.
A.had stopped B.stopped
C.has stopped D.would stop
14.They hurried there only to find the meeting canceled.In fact,they ______ at all.
A.might not have gone B.needn't have gone
C.mustn't have gone D.wouldn't have gone
15.The time has come ______ we make extensive use of nuclear energy.
A.when B.while C.as D.since
16.You and I could hardly understand each other,_________?
A.could I B.couldn’t you
C.could we D.couldn’t we
17.You ______ a new bicycle,since the one you lost the other day has already been found.
A.should not buy B.need not buy
C.need not have bought D.should not have bought
18.They _______ in spite of the extremely difficult conditions.
A.carried out B.carried on C.carried off D.carried forward
19.Children who are over-protected by their parents may become _______.
A.hurt B.damaged C.spoiled D.harmed
20.When Mr.Jones gets old,he will _______ over his business to his son.
A.take B.hand C.think D.get
21.His understanding made a deep impression _______ the young girl.
A.in B.on C.for D.to
22.They have been trying to arrive at a practical solution _______ the problem.
A.in B.to C.on D.with
23.In many American families,parents feel that children should make important
decisions _______.
A.to themselves B.on themselves C.of themselves D.by themselves
24.I find this treatment very _______ to my health.
A.advisable B.invaluable C.beneficial D.worthy
25.As a _______ president,his views are treated with respect when he is interviewed.
A.prior B.previous C.late D.former
26.It is not difficult to _______ the idea that machines can communicate information to us.
A.admit B.receive C.accept D.convince

1.C 非限定性的定语从句只能用which
2.B 主句是过去将来式,从句用一般过去式
3.B 其实根本就没有必要去
4.A When引导的定语从句
5.C hardly 表否定
6.B
7.B 继续的意思
8.C 意思是贯坏的
9.B 意思是传给
10.B impression on 固定搭配
11.B solution to 固定搭配
12.D 自己的意思
13.C 有意的
14.B 前任的
15.C 接受的