他用力拉动风箱，让炉火更旺。

He pumped the ___bellows hard to make the furnace flames stronger.

这台古董相机的皮腔可以平滑伸缩用于对焦。

The vintage camera's leather ___bellows expands smoothly for focusing.

公牛愤怒地吼叫，回声在山谷中回荡。

The bull ___bellows in rage, its echo bouncing through the valley.