To be a slave in this world is very different from being a slave in another.

盈利和可持续性必须齐头并进，它们并非相互排斥。

【译文】溺爱母亲会养出败家子，严格管教不会出凶暴奴仆。

Make it a rule never to give a child a book you would not read yourself.

一个好的模型是准确性和简洁性之间的折衷。