You won't know whether the coat fits you until you___it on.

问题描述:

You won't know whether the coat fits you until you___it on.
选项:A:will try B:have tried C:tried D:are trying
B 为什么?
应该是A才对吧.
主人公试穿衣服是未来的动作,还没发生呢,出题怎么也用过去式 won't

翻译为:
将来时,未来也不会)知道这件外套合不合适,直到你(已经)试过了.
这里要看,主人公试穿衣服,要发生以后,才能得到以上结论,所以用完成时,明白了?