-I am sorry i forget ( ) the letter for you

问题描述:

-I am sorry i forget ( ) the letter for you
-I will post it myself .
A .to post B.posting
C.post D.posted

A.to post
forget to do 表示忘记要做某事,就是事实上没有做
forget doing 表示忘记自己曾经做过某事.