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 drifter pulled out his harmonica while riding the train and played a tune over the _ noise.
[A]: train


[Q]: Steven's teacher made him redo the homework assignment, because he had failed to understand the _ .
[A]: assignment


[Q]: The contractor decides on wood for the siding, instead of vinyl, because the _ is sturdier.
[A]:
wood