I think that in mathematics, and maybe in life, you have to be willing to be a little bit lost.
The root of the problem is the failure to distinguish between operational effectiveness and strategy.
可持续性不仅仅是一种趋势,更是我们共同的责任。
我们几乎无法避免这样的推论:光是由同一种介质的横向波动组成的,这种介质也是电和磁现象的原因。