22.no one can besure if the car on display fits him or her until he or her ______ them

问题描述:

22.no one can besure if the car on display fits him or her until he or her ______ them
A)tries
B)will try
C)are trying
D)have tried

你可以看到if是引导条件状语从句,所以用一般现在时表将来,而until是引导时间状语从句,也是用一般现在时表将来.因为在时间和条件状语中都会用一般现在时表将来意义.