两个英语句子,
问题描述：
两个英语句子,
1.Don't get off the bus until it has stopped.
2.I didn't go to bed until mom came back.
为什么1句中要用完成时,而2不用?
答
1.直到公共汽车停下来了你再下车
2.直到妈妈回来我还没有去睡觉
你感觉下翻译