H?i ??ng x? s? ki?n thi?t mi?n B?c bao g?m 28 ??n v? thành viên, trong ?ó có 6 ??n v? t? ch?c quay s? chính th?c và c? ??nh hàng tu?n c? th? nh? sau:The hardest faults to discover are people who come about only Now and again—intermittent activities. They can be a result of bad connections, dust, Dust, corrosion or just damaged wiring or co