他解开外套的纽扣，让自己更舒服些。

He ___unfastened the buttons on his coat to make himself more comfortable.

你的鞋带松了，走路要小心。

Your shoelaces are ___unfastened, be careful when walking.

她解开了外套的扣子，因为房间里太热了。

She ___unfastened her coat because the room was too warm.