pithless

例句：

1. 1. The tree's trunk was pithless, making it easy to move.
   这棵树的树干是空的，很容易移动。
2. 2. The pithless core of the fruit is where most of its nutrients are stored.
   果实的空心部分是储存大部分营养的地方。
3. 3. The pithless part of the stem allows for better water absorption.
   茎部的空心部分有利于更好的吸水。