他熟练地用绳子打了个结固定帐篷。

He skillfully ___knotted the rope to secure the tent.

我的耳机线又缠在一起了，解不开。

My earphone wires ___knotted again and I can't untangle them.

绳子打结了，很难解开。

The rope ___knotted and became difficult to untie.

举重后，他的背部肌肉紧绷了起来。

After weightlifting, the muscles in his back ___knotted up.