Give the pupils something to do, not something to learn; and the doing is of such a nature as to demand thinking; learning naturally results.
The future of forestry lies in sustainable practices that balance economic growth with environmental stewardship.
我们工作中最大的回报是知道自己带来了改变。
粒子的概念只是近似的,并且只有在动量较小的极限下才有意义。
我在想,革命是不朽的。