The brain is like a muscle. When it is in use we feel very good. Understanding is joyous.
大脑就像肌肉。当它被使用时,我们感觉很好。理解是快乐的。
-- Carl Sagan 卡尔·萨根
The brain is like a muscle. When it is in use we feel very good. Understanding is joyous.
大脑就像肌肉。当它被使用时,我们感觉很好。理解是快乐的。
-- Carl Sagan 卡尔·萨根