salutary

这一反对意见是有益的，推动了理论的改进。

The objection is ___salutary, prompting refinement of the theory.

长途徒步证明是有益的，让他在数周的压力之后重新理清了思绪。

The long hike proved ___salutary, clearing his mind after weeks of stress.

入学考试的失败是一次有益的经历，迫使她重新思考自己的目标。

Failing the entrance exam was a ___salutary experience that forced her to rethink her goals.