1.The research requires more money than__1__.
A. have been put in
B.has been put in
C.being put in
D. to be put in

2.Overpopulation poses a terrible threat to the human race. Yet it is probably__2__a threat to the human race than environmental destruction.
A.no more
B. not more
C. even more
D. much more

3.It is not uncommon for there__3__problems of communication between the old and the young.
A.being
B.would be
C.be
D. to be

4.__4__at in his way, the situation doesn’t seem so desperate.
A. Looking
B.Looked
C.Being looked
D. To look

5.It is absolutely essential that William__5__his study in spite of learning difficulties.
A.will continue
B.continued
C.continue
D. continues

答案:
1.B
[解析]:看新编语法教程,里面说这里than后面是省略了it,还原应该是..than it has been put in

2.B
[解析]:上句说人口多对人类发展造成威胁.而大家要注意这个yet,yet常用于否定句和疑问句,
也就是说下句应该是一个"否定"上句的句子.,而not more ...than的意思就是 与其说是A ,不如说是B.
这句话.Yet it is probably not more a threat to the human race than environmental destruction.就是与其说是威胁了人类发展,还不如说是威胁了环境...

3.D
[解析]: 语法课讲了多少遍,for there to be,of there being.

4.C
[解析]:让我们做最简单的还原,这里的the situation 是逻辑主语,如果the situation looked at in his way.群众的looked是过去时,主动时态,而 the situation 是"被"看待的.怎么会是主动的呢?

5.C
[解析]: 这里是省略了should是用法