set of balls

例句：

1. 1.He collected a set of baseball cards for his son's birthday.
   他为儿子的生日收集了一套棒球卡片。
2. 2. The children played with their set of dolls in the park.
   孩子们在公园里和他们的小玩偶一起玩。
3. 3. She had a set of tennis rackets that she used to play on the court.
   她有一套网球拍，她用它们在球场上打网球。