问题补充:
It was only after she had read the papers Mary realized the homework before her was extremely difficult to complete.
A. when
B. that
C. which
D. what
答案:
A. when
(答案→)B. that
C. which
D. what
解析:句意:就是在玛丽读了文章之后,她才意识到她面前的家庭作业非常的难完成。这个句子中含有It was,首先要考虑它是不是一个强调句,把It was和横线去掉,这个句子仍然结构完整,语义清楚,所以说这个句子就是一个强调句,选B。