变松

例句：

1. 1. After a long day at work, I need to take a break and let my muscles loosen up.
   工作了一整天后，我需要休息一下，让我的肌肉放松。
2. 2. The old man tried to loosen the knot in his shoelace.
   老人试图解开鞋带上的结。
3. 3. She loosened her seatbelt and got out of the car quickly.
   她松开安全带并迅速下车。