Biconcave
a. 双凹的\\n[医] 双凹[形]的
🏥 医学释义
双凹面的，双凹（形）的
🗣️ 情景例句
Good. What do you think, Richard?
好。 你看呢 Richard？
He hasn't answered my letter yet.
他还没有给我回信。
The characters on the paper were white, and the rest of the paper was black.
纸上的汉字呈白色，其余部分成黑色。