问题补充:
is necessary us learn English well.
A. It, of, to
B. This, of, of
C. It, for, to
D. This, for, to
答案:
A. It, of, to
B. This, of, of
(答案→)C. It, for, to
D. This, for, to
解析:考察固定句型 It is +adj+for/of sb to do sth 当adj是人的一种品格时用of。题目中necessary不是人的品格,故选C句意:对我们来说学好英语是很有必要的。