The beauty of physics lies in its ability to explain the universe with a few simple principles.

自满是医学进步的敌人。

There are dark shadows on the earth, but its lights are stronger in the contrast.

The rule, or measuring rod, which the behaviorist puts in front of him always is: Can I describe this bit of behavior I see in terms of "stimulus and response"?

The most important things are hardest to tell,because words shrink their importance.It's not easy to let strangers care about the good things in your life.

永远不要停止学习，因为世界永远不会停止变化。