Taking history as a mirror, people-oriented and copper as a mirror, you can be well dressed, know the rise and fall by taking history as a mirror, know the gains and losses by taking people as a guide, and know the rise and fall by taking history as a mirror. "

"Sword" and "mirror" are synonyms. In other words, take history as a mirror and take history as a mirror; Take people as a mirror and people as a reference (you can see your own behavior)