阅读只为心灵提供知识的材料;是思考使我们所读的东西成为我们自己的。
The only limit to our realization of tomorrow is our doubts of today.
For every dollar you spend purchasing something substantial, expect to pay a dollar in repairs, maintenance, or disposal by the end of its life.
没有我们开采的金属,能源转型就无法实现。