问题补充:
My colleague has been recovering gradually since the operation, and it wont’ be long he comes back to work.
A. before
B. since
C. after
D. when
答案:
(答案→)A. before
B. since
C. after
D. when
解析:考查连词,before 意思“(直到…)才”,since意思“自从”,after意思“…之后”, when意思“当……时候”,句子意思“自从做完手术,我的同事一直在恢复,直到他回去工作用不了多长时间”,所以选A