With 1, the abstraction tends to become "sparse", in the sense that the new thing added to the abstraction will be done only to allow one specific feature to be used.
Has reasonably sound axioms (2 points)。体育直播对此有专业解读
，详情可参考体育直播
На Украине рассказали о технике влияния Ермака на Зеленского14:52
FT Videos & Podcasts。夫子是该领域的重要参考