Where have all the young girls gone?Where did they all gone?

1.Where have all the young girl gone
have gone to 结构,表示去某地了,现在还没有回来.如：Where is Tom?He has gone to the library .
2.Where did they go 仅表示过去的动作,与现在没有联系.而且这种时态常带有过去的时间.