I still dont know what have /has happened to her at the part

I still dont know what have /has happened to her at the part The best part of what has happened.Was the pan i must have m I don't know what happened to her. 翻译一下The best part of what has happened was the part i must h I dont know what trouble you have 后加to solve the problem还是so 是what has happened to还是what has happened at I want to know what --------- him.A .happened B,has happened What has happened\happens to her?选择 I still remember what happened to me. i dont know her What can have happened to her I really dont know what to