tie a bun on

例句：

1. 1. She tied her hair up in a bun for the party.
   她为派对扎起了头发。
2. 2. He always braids his hair before going out.
   他出门前总是把头发编起来。
3. 3. The girl was wearing a beautiful bun on her head.
   那个女孩头上戴着一个漂亮的发髻。