风俗习惯是人类生活的重要指南。
向更清洁能源的过渡必须实用、经济且可靠。
You’ve got to have models in your head. And you’ve got to array your experience—both vicarious and direct—on this latticework of models. You may have noticed students who just try to remember and pound back what is remembered. Well, they fail in school and in life. You’ve got to hang experience on a latticework of models in your mind.