i will not swim in such a dirty river unless you___A.will B.are going to C.come D.do为什么选D,而不是选A

问题描述:

i will not swim in such a dirty river unless you___
A.will B.are going to C.come D.do
为什么选D,而不是选A

unless后面要一般现在时,不能用将来时

unless you...引导一个从句,主将从现。

应为unless是引导的是从句,用一般现在时,do代替swim