Biorthogonality
[计] 双正交
🗣️ 情景例句
He was a dull man and you had to explain things very slowly to him.
他脑筋迟钝，你必须慢慢地给他解释事情。
He who has not tasted bitter knows not what sweet is.
不吃苦中苦，哪知甜中甜。
He has an old head on young shoulders.
他年轻又有见识。