single shrouded wheel

例句：

1. 1.The single tree in the park is very beautiful.
   公园里的这棵树非常美丽。
2. 2. She lives a single life without any family.
   她过着单身生活，没有任何家庭。
3. 3. He is a single man who has never married.
   他是一个从未结婚的单身男人。