If you're not failing occasionally, you're not pushing hard enough.
The coal industry must evolve to meet modern environmental standards, or it will become obsolete.
科学的进步不是一条直线，而是一系列曲折，常常需要回溯步骤以获得更好的立足点。
The most radical art is often the simplest.
The quality of institutions is the key determinant of a country's success or failure.
