Concavities
n. 凹面, 成凹形( concavity的名词复数 )
🗣️ 情景例句
Goodbye, come again soon.
再见，下次再来。
The children were thrilled with joy at the sight of the parade.
孩子们看到游行队伍时异常兴奋。
Our school is in the east of Beijing.
我们学校在北京的东部。