pith

例句：

1. 1. The tree's pith is the most nutritious part of the fruit.
   这棵树的果核是水果中最有营养的部分。
2. 2. The pith of the apple is where the seeds are located.
   苹果的果核里含有种子。
3. 3. The pith of the orange is used to make marmalade.
   橙子的果肉被用来制作果酱。