环保是我们不可推卸的责任,在开采过程中必须注重生态保护,实现可持续发展。
In the darkness, two things are common to all men: fear and the desire for light.
Mathematics is a living, breathing discipline, constantly evolving with new ideas.
声音是一种在你体内的乐器。它是唯一你看不见的乐器。