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.

The car engine outperformed the bus engine simply because the _ was inefficient during the test run.
bus

The weightlifter felt a lot more tough when working with barbells than with kettlebells, because the _ worked more complex muscle groups.
barbells

Tony tried his best but couldn't shovel the pile of coal because the _ was too small.

shovel