before have we seen it before and must forgotten it麻烦帮忙翻译下并且连起来,急

before have we seen it before and must forgotten it麻烦帮忙翻译下并且连起来,急
before have we seen it before and must forgotten it
麻烦帮忙翻译下并且连起来,急

before have we seen it before and must forgotten it麻烦帮忙翻译下并且连起来,急
We must have seen it before and forgotten it.
我们以前肯定见过,却忘了.

And before seen it, we must have it
forggotten.
sorry，这句真的是有困难~

we must have seen it before and forgotten it.
感觉多了个before啊