题目内容：

Why isn't Nancy going to meet us? 选择题?
Why isn't Nancy going to meet us?
It's my fault. I forgot all about ___her.
A:telephoning B:to telephone
C:to telephone to D:the telephoning to
答案是A 为什么B是错的?

优质解答

forget to do sth意为“忘记将要做的事”
forget doing sth 意为“忘记已做过的事”
此处显然事情已经发生了而且没有给nancy打电话,所以是A选项.