--You should have thanked her before you left.
--I meant , but when I was leaving I couldn’t find her anywhere.
A. to do
B. to
C. doing
D. doing so
网友回答
A. to do
(答案→)B. to
C. doing
D. doing so
解析：此处meant to do sth意为：本打算做某事，结果却没做。这里是不定式的省略。句意：——你应该走之前向她表示感谢。——我本打算那么做，可是我离开的时候，我找不到她。根据句意及语法选B。