If it ________, we ________ go to the Great Wall tomorrow.
A.rains; will B.is raining; will C.will rain; won't D.rains; won't
We all know that paper burns well in ________.
A.CO2 B.N2 C.O2 D.CO
Students are busy ________ for the coming test these days.
A.prepare B.prepared C.to prepare D.preparing
— Would you mind my opening the window?
— ________. It's good to let fresh air come into room.
A.Yes, I would B.Certainly C.Of course not D.You'd better not
She will be late ________ she gets up early.
A.if B.unless C.though D.because
— Mom, must I clean my room now?
— ________. You can clean it after finishing your homework.
A.Yes, you must B.No, you can't C.No, you needn't D.Yes, I don't have to
