What if there no water or air on the earth?
A. happen, is
B. will happen, is
C. will happen, will be
D. happen ,are
网友回答
A. happen, is
(答案→)B. will happen, is
C. will happen, will be
D. happen ,are
解析：句意：如果地球上没有水和空气，将会发生什么？根据句意判断，句子要用一般将来时，water为不可数名词，并且if 引导的状语从句用一般现在时表示将来所以用单数is ，故选B