if it ——tomorrow we will have a picnic..
A.won't rain
B.doesn't rain
C.isn't raining
D.n't rain
.B和C的区别是什么?
what if he ——?
A.A.won't come
B.doesn't come
C.isn't coming
D.wouldn't come
..与上题类似..可我也不明白B和C.