Here'a sentences written in my textbook.
Hello, I'm staying in roon 124. I've got a problem and I was wondering if you could help me. I seem to have misplaced my wallet somewhere; it could have been in the hotel.
'it could have been in the hotel' doesn't sound enough because of omitting subject. So, what if I change into followings to make it sound fully?
It could have been in the hotel WHERE I misplaced my wallet.
It could have been in the hotel THAT I misplaced my wallet.
THE PLACE where I misplaced my wallet could have been in the hotel.
Are all of the three sentences right?