我只是说了一个引子，但是我想这绝不是一个真正的大秘密。

I speak about that in the guide, but I guess it is not really a huge secret.

youdao

作为引子，你们可能已经知道了，一元微积分里面的一个小把戏，也就是求隐函数微分法。

And, just to motivate that, let me remind you about one trick that you probably know from single variable calculus, namely implicit differentiation.

youdao

他们热爱园艺，因为这不仅能减少杂物开销，还能锻炼身体，并且是一个非常好的户外活动的引子。

They loved gardening because it reduced their grocery bill, improved their health, and gave them an excuse to be outside.

youdao

This is a course about justice and we begin with a story.

这是一门讨论公正的课程,我们以一则故事作为引子。

耶鲁公开课 - 公正课程节选