tie molecule

例句：

1. 1. I need to tie my shoelaces before I go out.
   我需要出门前系好鞋带。
2. 2. The children were busy tying their shoes.
   孩子们忙着系鞋带。
3. 3. She tied the parcel securely with a ribbon.
   她用一条带子把包裹系得紧紧的。