我知道，我感受到词语隐藏的含义。
I know, I feel the meaning that words hide.
The PAC learning framework provides a formal way to quantify the learnability of a concept class.
拥有过去是一回事，被过去挟持是另一回事。
没有人比说真话的人更招人恨。
The key to breakthrough is not just hard work, but also the courage to challenge existing paradigms.
突破的关键不仅在于努力工作，还在于挑战现有范式的勇气。
文学应该让人不安，应该提出问题，而不是给出答案。