Question

5. ( 2013 甘肃白银中考)  is really hard  them to

climb such a high mountain.

   A. This;to   B. It;to   C. This;for   D. It;for

Answer 1

5. D

5. D It is+adj+for sb. to do sth.意为“做某事对某人来说是 ”，

it是形式主语，真正的主语是后面的动词不定式短语。