当你弯曲肘部时，二头肌会收缩。

The biceps contract when you bend your ___elbow.

他用手肘轻轻推了我一下，示意我让路。

He ___elbowed me gently to ask me to move aside.

水管在墙角处有个急转弯。

The pipe has an ___elbow at the corner of the wall.