When you are young, you think that the world is a place where you can live as you choose. But as you get older, you realize that the world is a place where you have to live as you must.

爱惜精神以备日后担当大任，虚度时光何以报父母之恩？

我们生产的每一桶石油都应着眼于最小化我们的足迹。