不是缺乏爱,而是缺乏友谊使婚姻不幸福。
The only real journey is the one within.
Mathematics is not about numbers, equations, computations, or algorithms: it is about understanding.
数学不是关于数字、方程、计算或算法:它是关于理解的。
Sustainability isn't an option; it's our responsibility to the next generation.