问题
选择题
--Haven't you seen Mr. Wilson at the lecture?
--Yes, but he had left _________ I could ask him any questions.
A．when
B．before
C．after
D．as
答案
答案：B
此题考察的是过去完成时，had +动词的过去分词，表示发生在过去的过去的事情。
搜题请搜索小程序“爱下问搜题”