美国没有永恒的敌人,也没有永恒的朋友,只有永恒的利益。
Mathematics is not a deductive science—that's a cliché. When you try to prove a theorem, you don't just list the hypotheses and then start to reason. What you do is trial and error, experimentation, guesswork.
True leadership in fisheries means balancing economic needs with environmental responsibility.