种一棵树最好的时间是20年前,第二好的时间就是现在。
我们必须在经济增长和环境管理之间取得平衡。
课程必须被视为帮助孩子解释自己的经验并指导他进一步经验的手段。
量子力学的本质在于它提供了一个数学框架,用于描述原子和亚原子粒子的行为。
People are curious. A few people are. They will be driven to find things out, even trivial things. They will put things together, knowing all along that they may be mistaken. You see them going around with notebooks, scraping the dirt off gravestones, reading microfilm, just in the hope of seeing this trickle in time, making a connection, rescuing one thing from the rubbish.
I don't compete with anyone but myself. My goal is to be better than I was yesterday.