Coal is not just a commodity, it's a commitment to America's future.

I'm not a girl who needs to be saved. I'm a girl who saves herself.

The truth is not in the facts, but in the way we remember them.

Never stop learning; the world is always evolving.

The most beautiful as well as the most ugly inclinations of man are not part of a fixed biologically given nature, but result from the social process which creates man.

如果时空穿梭是可能的，那从未来穿越回来的旅客在哪里呢？