为初学者服务。这是我的帖子的宗旨。我也是个初学者（强调了无数遍了） ，我以我的理解把初学者觉 得难懂的东西用浅显的语言写出来。 -For beginners. This is my card. I am a beginner (emphasized countless times), I with my understanding of the beginners Too difficult things written in plain language.