The concept of probably approximately correct (PAC) learning has been foundational in computational learning theory.

解释：每种药材都有其独特的功效，而方剂则是将多种药材巧妙配伍以发挥更大效用。

最重要的是，你必须要有勇气跟随你的内心和直觉。

决不要害怕刹那－－永恒之声这样唱着。

Investing in cleaner coal technologies is investing in our planet's future.

To write is to resist oblivion.

Sustainability isn't a trend; it's a responsibility.

How will you use these gifts？ And will you take pride in your gifts or pride in your choices？