what happened 和WHAT IS HAPPEND的区别区别在哪里啊?还有个WHAT IS HAPPENING,发生了什么应该是WHAT HAPPEND 那WAHT IS

what happened to 和what happened What happened和what's happened有什么区别呀? What has happened和What was happened区别 what happened ?和what has happened ?的区别 What had happened?What had happened?What had happened? What happened 的意思和用法 是What happened 还是what’s happened what happened=what's happened吗? what happened 和what did happen的区别 what happened和what is going on 的区别急! what happen和what happened有什么区别 what happened/what was happened/what is happened/what happen/what is happeniwhat happened/what was happened/what is happened/what happen/what is happening这些用法都有吗 what happens what was happened what happens what is happening的区别和用法? what happened at last? what happened on What Happened to Us what happened then Dear,what happened to