I regret ________ a present to my friend when he got married last month.
问题描述：
I regret ________ a present to my friend when he got married last month.
A.to have not made
B.not making
C.not having made
D.having not made
这是2004年北京某所大学的考研题，参考答案给的是A，可是我想不通
答
A 是对的.
regret to do sth：后悔没做什么事
regret doing sht：后悔做过什么事
所以用to do
to have not made:现在完成时,表示直到现在也没有做,所以选A