问题
选择题
24. You ought to have put the milk in the refrigerator, and now ________sour.
A.it smell
B.it is smelt
C.it smells
D.it is smelling
答案
答案:C
考查时态。句意:你应该已经把牛奶放进冰箱了,可是现在闻起来酸了吧!结合语境可知下文描述的是现在客观存在的状态,故用一般现在时态,选C。