老师你好,语法书里说'someone has gone to a place'means that he is in that place now.
'someone has been to a place' means that he went to that place,but now is back.
但是为什么'Joe and Lisa are on holiday in Japan.They've been to Japan once before.'可以说成'This is the second time they've been to Janpan.'
她们还在日本,还没回来不是吗?为什么用been to?