【题目】He was told that it would be at least three more months _____ he could recover and return to work.
A. when B. since
C. before D. that
在线课程【答案】C
【解析】
试题句意：他被告知这至少还要三个月才能恢复回去上班。这里使用了固定句型：It will be+一段时间+before…的句型，“要多久才…”, since也可以和一段时间连用，但是句型是：It is/has been+一段时间+since…”,所以选C。