Overhead, without any fuss, the stars were going out.

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"?

快乐的最好方式是让别人快乐。

可持续发展不是一种选择，而是我们对下一代的责任。

译文：少年不知道早起勤奋学习，到老了后悔读书少就太迟了。赏析：人在年轻时，精力旺盛，正是勤奋读书，努力奋斗的时候。