膨胀的概念表明,宇宙在大爆炸后不久经历了一段极其快速的扩张期。
The concept of inflation suggests that the universe underwent a period of extremely rapid expansion shortly after the Big Bang.
Coal miners are the unsung heroes of America's industrial strength.
科学的本质是提出正确的问题。
Stick to the rivers and the lakes that you're used to