hollow
/ˈhɑloʊ/
a cavity or space in something
中文释义：洞；凹陷处；空腔
The rabbit hid inside a hollow in the tree trunk.
兔子躲在树干的一个洞里。
Geologists studied the hollow formed by the ancient lava flow.
地质学家研究了古代熔岩流形成的凹陷处。
/ˈhɑloʊ/
a cavity or space in something
中文释义：洞；凹陷处；空腔
The rabbit hid inside a hollow in the tree trunk.
兔子躲在树干的一个洞里。
Geologists studied the hollow formed by the ancient lava flow.
地质学家研究了古代熔岩流形成的凹陷处。