【题目】I see no reason why they shouldn’t go on playing for another four or five years ________ they are fit enough.
A. unlessB. so thatC. though D. providing that
在线课程【答案】D
【解析】
试题分析：考查状语从句关系词的用法及句意理解。句意：假如他们足够健康，我找不到他们不应该再玩四五年的理由。A.除非；B.以便于，结果；C.尽管；D.假如，以……为条件。故D正确。