I'm not afraid to speak my mind.
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.
The future of energy lies in balancing immediate needs with long-term environmental goals.
采石业必须与技术一起发展，否则就有落后的风险。
To be human is to be vulnerable.