n. a cavity or space in something
n. a small valley between mountains
v. remove the interior of
a. not solid; having a space or gap or cavity
n. 洞, 窟窿, 山谷
a. 空的, 虚伪的, 空腹的, 凹的
vi. 形成空洞
vt. 挖空
1. The tree trunk was hollow inside.
树干内部是空心的。
2. She felt hollow after hearing the bad news.
听到坏消息后，她感到心里空荡荡的。
3. He found a hollow rock by the river.
他在河边找到了一个空心的岩石。