Respuesta :
The sentence to be revised to replace the preposition is I don’t know where Carlos is staying at.
What a preposition is
Its a governing word usually preceding a noun or pronoun and expressing a relation to another word.
The sentence I don’t know where Carlos is staying at should be revised so that the preposition at the end will be eliminated.
Read more about preposition here:
https://brainly.com/question/17476214