separating the useful from the waste

例句：

1. 1. The twoteams are competing for the championship.
   两队正在争夺冠军。
2. 2. The children were playing with theirtoys in the park.
   孩子们在公园里和他们的小玩具玩耍。
3. 3. The teacher separated thestudents into different groups.
   老师将学生分成了不同的小组。