数学的本质在于它的自由。

对你的产品发誓。如果你不这样做，其他人也不会这样做。

Sustainable agriculture is not a slogan but a responsibility—we must preserve green mountains and clear waters for future generations.

The most successful societies in the future will be those that can combine the efficiency of market economies with the social cohesion provided by traditional values.

选择很简单：要么我们现在保护自然，要么我们以后付出代价。