心灵需要书本，就像一把剑需要磨刀石。
A mind needs books like a sword needs a whetstone.
Farmers are the first environmentalists, working with nature every day.
"There are two occasions when the sacred beauty of Creation becomes dazzlingly apparent, and they occur together. One is when we feel our mortal insufficiency to the world, and the other is when we feel the world's mortal insufficiency to us."
学习是通过修改符号结构来提高性能的过程。
机会并不会如影相随，所以当它到来的时候，你最好抓住。