每一个天使都是可怕的。

唯一真正的优雅在于思想；如果你有了这一点，其余的一切都源于此。

Teaching is not about imparting everything, but about guiding at the right moment.

We should focus on both short-term gains and long-term value creation.

学习数学的唯一方法就是做数学。