在理论物理学的领域里，每一个发现都会带来新的问题和挑战。

煤炭的未来不仅仅是开采，而是我们如何负责任地将其融入不断变化的能源格局。

化学的进步以新元素的发现和分析方法的改进为标志。

I think that age is a very high price to pay for maturity.

定义就是限制。

The only service a friend can really render is to keep up your courage by holding up to you a mirror in which you can see a noble image of yourself.