She looks sad. Could you please tell me that prevents her from being as happy as before?
A. what it is
B. it is what
C. how it is
D. it is how
网友回答
(答案→)A. what it is
B. it is what
C. how it is
D. it is how
解析：本题含有强调句型，若把It is……that去掉，则很容易地看出what引导的宾语从句，what在从句中充当主语。故选A。