We are tired of doing homework every day; most of is of no use but of mechanical drill.A

问题补充：

We are tired of doing homework every day; most of is of no use but of

mechanical drill.

A. a lot of; it

B. the number of; which

C. a number of; it

D. a great deal of; which

答案：

(答案→)A. a lot of; it

B. the number of; which

C. a number of; it

D. a great deal of; which

解析：本题考查修饰不可数名词的形容词短语，homework是不可数名词所以排除BC；句中分号说明第二句不是定语从句，用it 代替homework。