拧紧松动端

lighten the mood───舒缓情绪；放松心情

tighten the laws───收紧法律

tighten the screw───拧紧螺丝

tighten the purse strings───勒紧钱袋

lighten the atmosphere───缓和气氛

tighten the law───收紧法律

at a loose end───闲着；无事做

be at a loose end───不知做什么好；闲着无事；无所事事

tighten the screw on someone───拧紧某人的螺丝

Leave the end hanging loose so you can pull it to tighten the strap.───让带子的未端突出如一个松的折角。