instruction:
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.
question:
The professor preferred to teach with the books instead of the computers, because the _ were out of date.
answer:
computers


question:
The hand of the little girl could not reach the top of she shelf because the _ is too tall.
answer:
shelf


question:
The rock was more special than the stone because the _ was from a normal area on the mountain.
answer:

stone