当最后一棵树被砍倒，最后一美元将失去意义。
The best ideas often come from unexpected places.
Your outer journey may contain a millionsteps; your inner journey only has one: the step you are taking right now.
The writer must be able to superintend himself and criticize himself.
不断追求智慧，是人生的最高目标。
The key to solving complex problems is to break them down into smaller, more manageable parts.