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:
She had just gotten her first period not long ago, so she used a tampon with a string. She struggled to use the tampon because the _ was short.
answer:
string


question:
While the man modified the height of the bike, the boy rode the tricycle, because the _ was the incorrect height.
answer:
bike


question:
The man moved money from the safe into the wallet until the _ was empty.
answer:

safe