【题目】It will be quite a long time _______ she is back again, so don't be too cross with her.
A.that
B.since
C.before
D.until

【答案】C
【解析】句意：要很久她才能再回来，所以不要太生她的气。句型"It+be+time+ before…要过很久才……"。故选C。