"The truth is rarely pure and never simple."
在数学中，提出问题的艺术必须比解决问题更有价值。
Life is not about what you can’t do, it’s about what you can do.
孩子们值得拥有挑战他们的书，而不仅仅是娱乐。
The only time a dog gets complimented is when he doesn't do anything!