how long do you think it will be___china sends a manned spaceship to the moon?a whenb before用哪个?
问题描述:
how long do you think it will be___china sends a manned spaceship to the moon?
a when
b before
用哪个?
答
B before
因为跟的是一段时间(HOW LONG)
如果用when要跟确切的时刻