How long do you think it will be __ China sends a manned spaceship to the moon?

问题描述:

How long do you think it will be __ China sends a manned spaceship to the moon?
ow long do you think it will be __ China sends a manned spaceship to the moon?
A.after B.until C.that D.before

D,记住before在疑问句中常与将来时连用,表示 过多久才.