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.

[EX Q]: He had to use the sink in the toilet instead of the one in the kitchen, because the sink in the _ had a low water pressure.
[EX A]: kitchen

[EX Q]: The essay on microbiology was more interesting than the one written on statistics. _ must be an interesting subject.
[EX A]: microbiology

[EX Q]: It took longer to clean the fish tank than the dog cage because the _ was dirtier.
[EX A]:
tank