Plano-concave
a. (透镜)平凹的
🧩 词语组成解析
a. （透镜）平的
concave
['kɔn'keiv]
n. 凹面，成凹形;
adj. 凹的;
vt. 使成凹形;
🗣️ 情景例句
My visa is multi-entry; it allows me to exit the country and then re-enter, as ofter as I like.
我的签证是往返签证，我可以随便进出这个国家。
Whatever he does, don't say a word.
不管他做什么，你都不要讲话。
Triple gun-decks mounted sixty-four bronze cannon.
三层的火炮甲板上装着64门青铜加农炮，