她加入了一个教师工会，以争取更好的工作条件。

She joined a teachers' ___union to advocate for better working conditions.

工厂工人组建了一个工会来协商他们的工资。

The factory workers formed a ___union to negotiate their salaries.

他是当地消防员工会的活跃成员。

He is an active member of the local firefighters' ___union.