Concave tree of region
[计] 区域凹树
🧩 词语组成解析
concave
['kɔn'keiv]
n. 凹面，成凹形;
adj. 凹的;
vt. 使成凹形;
tree
[tri]
n. 树;木料;树状图;宗谱;
vt. 把…赶上树;使处于困境;把鞋型插入（鞋内）;
of
[əv]
prep. 关于;属于…的;由…制成;
aux. 助动词 [非标准用语、方言] =have [主用于虚拟语气];
🗣️ 情景例句
Thanks a million, Mr. Lee, for what you have done for me.
非常感谢你为我所做的一切。
John has built up his own business.He owns a hotel.
约翰建立了他自己的生意，他拥有一家宾馆。
Is the fire out?
火熄了吗？