我需要一个夹子来固定这些纸板。

I need a ___clamp to hold these cardboard sheets together.

修车时他用夹具把零件固定住。

He ___clamped the car part tightly while repairing it.

学校决定严格限制学生使用手机的时间。

The school decided to ___clamp down on students' mobile phone usage time.