The truth is, I am not a very good person. But I am trying to be better.
Children's books should challenge as well as comfort.
A man knows when he is growing old because he begins to look like his father.
物体的加速度与所受的合外力成正比,与物体的质量成反比。加速度的方向与合力的方向相同。
Curiosity and persistence are the driving forces behind scientific breakthroughs.