catalyst

这种酶在消化过程中起到了催化剂的作用。

This enzyme serves as a ___catalyst in the digestive process.

这种金属在化学反应中起到了催化作用。

This metal acts as a ___catalyst agent in the chemical reaction.

这位老师是激发学生创造力的重要催化剂。

The teacher was a key ___catalyst in inspiring students' creativity.