在平面直角坐标系中，已知抛物线经过A（﹣4，0），B（0，﹣4），C（2，0）三点．

—The difficult maths problem has been solved by Tom at last.

— Indeed; and the ___ way Tom worked out the problem impressed the teacher deeply.

①有利于弘扬中华传统美德        ②有效督促子女更好地履行义务

③体现法律是由国家制定的        ④只对年轻人具有一定的约束力