TASK DEFINITION: You need to answer a given question containing a blank (_). Your answer must be one of the two objects mentioned in the question, for example "trophy" and "suitcase". Your answer must not contain a word that is not present in the question. Please don't use articles (e.g., the, a) before the answer.
PROBLEM: Mary was unsure if the spot on the couch was from the pen or marker, then she realized it couldn't be the _ because the cap was on.

SOLUTION: marker

PROBLEM: The thief put all of the items from the safe into his bag until the _ was full.

SOLUTION: bag

PROBLEM: The landlord chose to allow cats in his units, but not dogs. He thinks that _ are dirtier.

SOLUTION:
dogs