量子电动力学的发展表明，粒子的概念并不像曾经认为的那样简单。

是心灵使身体富有。

Success is not the key to happiness. Happiness is the key to success. If you love what you are doing, you will be successful.

I was looking for the key for years, but the door was always open.

Sometimes the simplest ideas are the strongest.

解释：情绪变化会影响身体生理反应，如贪心时口水增多，悲哀时流泪，体现了情绪与健康的关联。