免费的疫苗比昂贵的治疗更有价值，但更难推广。

"To a great mind, nothing is little."

晏子春秋

We must mine coal responsibly today so that our children inherit both energy security and a healthy environment.

世界是一座监狱，其中单独监禁更可取。

最小的行动，乘以百万次，就能改变世界。