If you're not stubborn， you'll give up on experiments too soon. And if you're not flexible， you'll pound your head against the wall and you won't see a different solution to a problem you're trying to solve.

数学证明的美在于它的优雅以及它以清晰简洁的方式揭示潜在真理的方式。

Collaboration in mathematics can lead to discoveries that no single mind could achieve alone.

长城汽车的目标是成为全球SUV领导者。

世界是一个伟大的时钟，我们是其中的指针。