-I joined the League May 4th, 20ll. What about you
-I have been a League member three years ago.
A. in; for
B. on; for .
C. in; since
D. on; since
网友回答
A. in; for
B. on; for .
C. in; since
(答案→)D. on; since
解析：此题重点考查介词的基本用法。确指某一天的时候要用介词on。Since表示自从…后跟点时间，常用在完成时中。