M? th?y ng??i ch?t nh?ng ch?a ch?t là ?i?m gì? Gi?i mã gi?c m? th?y ng??i ch?t nh?ng ch?a ch?t và nh?ng con s? might m?n The hardest faults to locate are those that occur only From time to time—intermittent situations. They may be because of lousy connections, du