实现明天的唯一限制是我们今天的疑虑。
The only limit to our realization of tomorrow is our doubts of today.
译文：从深山里开采出来，经过千锤百炼，烈火焚烧也毫不在乎。就算粉身碎骨也不怕，只为在世上留下清白的名声。
The future of coal lies in cleaner technologies and smarter resource management.
"She was free in her wildness, she was a wanderess, a drop of free water. She belonged to no man and to no city."
Productive thinking is characterized by the sudden appearance of the solution as an insight.