【题目】He will come to understand your efforts sooner or later. It's just a matter of ________.
A.luck
B.value
C.time
D.fact

【答案】C
【解析】句意为：他迟早会理解你付出的努力的。这只是个时间问题。luck运气；value价值；time时间；fact事实。根据句意选C。