1·Don't clench your fists because it can lead to tightening the arms, shoulders, and neck.
不要握紧你的拳头，因为它会导致手臂、肩膀和脖子紧绷。
2·They leap to their feet, clench fists and let out long screams, clawing at the ground and air.
他们跳起来，握紧拳头，发出长长的尖叫声，抓向地面或空中。
3·So the next time you're faced with a choice that takes self-control, clench your fist or firm that bicep. Your will might firm up, too.
因此当你下次面临和自制力有关的抉择时，握紧你的拳头，又或者是绷紧你的二头肌，你的意志力也会随你的肌肉坚实起来呢！
4·If you hold your fingers over your lips or clench your jaws when you practice speaking American English you will find yourself much closer to native speakers.
当你练习说美国英语的时候，如果你用两个手指压住你的上下嘴唇，或者握紧你的下巴，你将会发现你的发音会十分接近美国本土人士的发音了。
5·You clench the steering wheel and turn the ignition again.
你握紧方向盘，再一次发动了点火开关。