the worker has liwed here for twenty years____ A.since twenty years agoB.since he come here

题目

the worker has liwed here for twenty years____ A.since twenty years agoB.since he come here
C.twenty years ago D.twenty years before
原因啊 .

答案

答案：C
原因：
A.since与ago两介词重复
B.应是过去式,把come改成came
C.固定搭配
D.无此说法（现在完成时的时间状语只有1.since+过去式从句 2.时间段+ago）