在数学中，真理总是相对于你所在的系统而言的。

Sustainability isn't a choice; it's our responsibility to future generations.

理解某事的最好方法就是尝试去改变它。

The best part of being in a group is having brothers to share everything with.

你只需要写出一句真实的句子。写出你所知道的最真实的句子。