Sustainability isn't an option—it's a responsibility we owe to future generations.
社会系统是个人与个人之间、群体与群体之间关系的网络。
The secret of change is to focus all of your energy not on fighting the old, but on building the new.
在语言中,词语和它们所指的事物之间没有一对一的对应关系。
购物可以说是最后剩下的公共活动形式。