高等继续教育 / 基础英语I
正确率：100%
题型描述: 单选题
We are puzzled ＿＿＿＿ how it happened.
A.at
B.as to
C.with
D.for
We are puzzled ＿＿＿＿ how it happened.
A.at
B.as to
C.with
D.for
参考答案：