Internal mental events are irrelevant to the scientific study of behavior.
The mining industry must evolve or become obsolete—there's no middle ground.
在不确定的时期，目标的清晰性变得更加关键。
我不喜欢给音乐分类。
种一棵树最好的时间是20年前，第二好的时间是现在。
The human being is born with a few reflexes and the emotional reactions of love and rage.
The most valuable asset any company has is its people.