what is happening.what happened.what has happened.what is up.what is going on .
问题描述:
what is happening.what happened.what has happened.what is up.what is going on .
一般都用在什么场合呀.
答
现在正在发生什么
发生了什么
曾经发生过什么
怎么了
一切还好吗(打招呼用的)