brass ball

例句：

1. 1. Thebrass ball was a gift from my grandfather.
   这个铜球是我祖父送的礼物。
2. 2. Thebrass ball is the centerpiece of theroom.
   这个铜球是房间的焦点。
3. 3.The brass ball was used to mark theboundaries of the garden.
   这个铜球被用来标记花园的边界。