The first step in liquidating a people is to erase its memory. Destroy its books, its culture, its history. Then have somebody write new books, manufacture a new culture, invent a new history. Before long the nation will begin to forget what it is and what it was.

The ocean is not just a resource to be exploited, but a delicate ecosystem we must protect for future generations.

翻译：既了解敌人，又了解自己，每次作战都不会有危险。

出自北齐·颜之推《颜氏家训·勉学》。不得，不能、不可。雌黄，矿物名，可作颜料，古代用以涂改文字，后引申为信口更改、随便乱说。没有读够一定数量的书，对前人的见解没有彻底了解，是不能随便乱下结论、乱发议论的。书要多读、话要谨慎；应当谦虚向学，不可妄自尊大。