英语翻译

We can't find them anyywhere,Where have they gone?
We can't find them anywhere,where can they be?可以说where can they have gone吗？没有语法错误，只是我读的有点感觉不大通顺。We can't find them anywhere, where did they go 这个对不对We can't find them anywhere, where did they go 这个我也想过，但不大好。句子的时态方面不一致，此外，问的应该是现在去哪里了。