abbr. 概率分部函数（Probability Distribution Function）
🗣️ 情景例句
He did not win, but at least he made the effort.
他虽然没有获胜，但至少已经尽了努力。
By falling we learn to go safely.
吃一堑，长一智。
We are very proud of him.
我们真为他感到自豪，