nested D O

例句：

1. 1. The books are nested in the shelves.
   书放在书架里。
2. 2.The layers of the cake were nested perfectly.
   蛋糕的层次被完美地堆叠着。
3. 3. The nested structures of the forest are fascinating to explore.
   森林中层层叠叠的结构令人着迷，值得探索。