He clamped his lips together.

他紧闭双唇。

I clamped a hand on his shoulder.

我用一只手紧紧抓住他的肩膀。

Her lips clamped tightly together.

她的双唇紧闭。

The army clamped a curfew on the city.

军队对这座城市实行了宵禁。

She clamped her hand against her mouth.

她用手紧紧捂住嘴。