树干

zhè shù gàn lǐ miàn shì kōng de

这树干里面是空的。

The tree trunk was hollow inside.

tā chī chī de kào zhe shù gàn wàng zhe yǎn qián de yī piàn xīn lǜ chū shén

他痴痴地靠着树干，望着眼前的一片新绿出神。

Leaning against the tree trunk, he gazed at the greenery stretching before him.