knee-high to a duck

例句：

1. 1. The shoes are knee-high, which makes them easy to wear.
   这些鞋子是膝盖高的，穿起来很方便。
2. 2.She wore a knee-high skirt that matched her dress perfectly.
   她穿着一条膝盖高的裙子，与她的连衣裙完美搭配。
3. 3.The child was knee-high to the ground, unable to stand up.
   这个孩子膝盖高到地面，无法站立。