Lies can never changes fact. 谎言终究是谎言。

Let the cat out of the bag. 泄漏天机。

Let sleeping dogs lie. 别惹麻烦。

Let bygones be bygones. 过去的就让它过去吧。

Learn to walk before you run. 先学走，再学跑。

Learn not and know not. 不学无术。

Learning makes a good man better and ill man worse. 好人越学越好，坏人越学越坏。

Learn and live. 活着，为了学习。

Knowledge makes humble, ignorance makes proud. 博学使人谦逊，无知使人骄傲。

Knowledge is power. 知识就是力量。