自由不是恩赐,而是必须争取的权利。
对幼儿来说,妈妈的声音是具有特殊意义的参照物。
I know how much work it takes to get to the top, but even more to stay there.
"The city is a labyrinth of memories, each street a thread in the web of time."
数学家的工作永无止境;总有新的问题要问,新的谜题要解。