粒子的概念只是近似的，并且只有在动量较小的极限下才有意义。

The greatest weapon against stress is our ability to choose one thought over another.

最好的故事是那些永远陪伴你的故事。

每个故事都是一次旅程，每次旅程都是一个故事。

A book can be a friend, a teacher, and a doorway to another world.

The past is never dead. It's not even past.

"The value of a man should be seen in what he gives and not in what he is able to receive."

你写的文本必须向我证明它渴望我。