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.

[Q]: The engineer created robots to replace the algorithms at solving the puzzle. The _ were more advanced.
[A]: robots


[Q]: The cleaning crew always used rags instead of washcloths, although the _ tended to wear out quickly.
[A]: rags


[Q]: They were trying to fly the kite at either a low or high altitude. The _ altitude was difficult to maintain.
[A]:
low