种树的最佳时间是20年前，第二好的时间是现在。

Understanding the computational complexity of learning problems is essential for developing efficient algorithms.

平衡市场判断与风险控制。

勇气是在压力之下展现出的优雅。

The beginning is the most important part of the work.

过去从来不仅仅是过去。它始终是现在的基础。

A picture must be grasped at once, as a whole, like a piece of music.