What do you think has made her so upset? ____, I believe.

来源：百度知道 编辑：UC知道 时间：2024/06/07 19:05:52
A.She failed her exam
B.Failing her exam
C.To have failed her exam
D.Failed her exam

b,what 肯定是问一个名词的答案，因此是ing form

B
这里应该填一个名词性的短语，用来做主语。
还原回答的句子是：
Failing her exam has made her so upset,I believe