问题补充:
It is necessary the magazines in time.
A. to us to return
B. for us to return
C. to us returning
D. that we had returned
答案:
A. to us to return
(答案→)B. for us to return
C. to us returning
D. that we had returned
解析:以It作形式主语或形式宾语引导的复合句结构中,如果这形容词指行为的性质。使用这样的句型:It+表行为性质的形容词+for sb.+不定式。