--- Look at the black clouds. It ______ soon.

　 --- Sure. If only we ______ out.

A. is raining; didn’t come

B. is to rain; won’t start

C. will rain; haven’t started

D. is going to rain; hadn’t come

-- Mum, I've been studying English since 8 o'clock ________ I go out and play with Tom for a while?

-- No, I'm afraid not. Besides, it's raining outside now.

[　　]

It was raining outside,　　　,I couldn’t find a taxi.

A.to make things better　　　　　　　B.to make things worse

C.still worse　　　　　　　　　　　　D.still better

21.—It is raining cats and dogs.

22.　—　　　..

23.

— I’d like to go home now.

　 — Why not stay here for the night? It is so late now. ____, it is raining so hard.

　 A. Besides　　　 B. Therefore　　　 C. Instead　　　 D. As a result