She tied a pretty knot at the end of her pigtails.

她在辫子的末梢打了一个花结。

《新英汉大辞典》

Take the wide end with your left hand and bring it to your left and then behind the knot-passing it off to your right hand.

最后用你的左手把宽的一边拉到左边，再放到结后面，然后用右手接住。

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Pick up the running end of the rope (the end that will be loose after you tie the knot).

拿起绳索的活动末端（在完成绳结后，末端将变得松散）。

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But even as gay rights advocates celebrate the nearly 10, 000 same-sex couples who've officially tied the knot, they are gearing up to fight a measure that might end same-sex marriage altogether.

NPR: Looming Legal Fight Clouds Gay Marriage Milestone