More amd more people have realised we won't have cleaner wat
More amd more people have realised we won't have cleaner water to drink unless something _____ soon A.was done B.will be done C.to be done D.is done 请详细讲讲,另外,be done在这里是什么意思
越来越多的人意识到,如果我们不马上做些什么,我们将没有干净的水可以饮用。 unless是从属连词,引导条件状语从句,含有否定意义,相当于if条件状语从句的否定形式。所以unless = if not。注意:unless引导的条件状语从句和if条件状语从句,与其它时间状语从句一样,用一般现在时代替将来时。...