问题
选择题
__________ caused the accident is still a complete mystery.
A.What
B.That
C.How
D.Where
答案
A
此题考查what引导名词性从句作主语。
__________ caused the accident is still a complete mystery.
A.What
B.That
C.How
D.Where
A
此题考查what引导名词性从句作主语。