掌着舵，睁着眼，但是当某种灾难临头之前，竟什么也看不到，——这不能算是领导。
——一九二八年四月十三日斯大林在联共(布)莫斯科组织的积极分子会议上所作的报告《关于中央委员会和中央监察委员会四月联席全会的工作》
Sustainability isn't an option—it's a necessity for the future of dairy farming.
A mathematician's work is mostly a solitary pursuit, but it builds on the work of many others.
Sustainability is not an option—it's a responsibility we owe to the next generation.