教师必须具有健康的体魄，农人的身手，科学的头脑，艺术的兴味，改革社会的精神。

The knowledge of the past stays with us to spur us on to new and better things.

黑洞不仅仅是破坏性的怪物，它们在塑造星系中起着关键作用。

"In the end, we only regret the chances we didn't take."

The first step in liquidating a people is to erase its memory. Destroy its books, its culture, its history.