Biconcavity
n. biconcave的变形
🗣️ 情景例句
We have four people in the family, my parents, my elder brother and I.
我家有 4 口人，我的父母，我的哥哥和我。
I wonder what makes you unhappy.
我不知道是什么使你不快乐。
He loved to be told that one of his imaginary products was temporarily out of stock and he would faithfully promise to call again at some future date, but of course he never did.
他爱听售货员说他想像出来的那种东西暂时脱销，于是他就煞有介事地许诺改天再来光顾。当然，他再也不会来了。