煤矿工人是美国工业实力的无名英雄。
Coal miners are the unsung heroes of America's industrial strength.
Society can and does execute its own mandates， and if it issues wrong mandates instead of right， or any mandates at all in things with which it ought not to meddle， it practices a social tyranny more formidable than many kinds of political oppression， since， though not usually upheld by such extreme penalties， it leaves fewer means of escape， penetrating much more deeply into the details of life， and enslaving the soul itself.
La imaginación es el arma más poderosa que tenemos contra la realidad.
数学中最重要的技能是清晰思考的能力。
如果你不能，你必须。如果你必须，你就能。