问答题
A.C1y1+C2y2+y3B.C1(y1-y2)+C2(y1-y3)C.C1(y1-y2)+C2(y1-y3)+y3D.C1(y1+y2)+C2(y1+y3)+y3
A.Christopher D HartB.Ting SunC.Roberta D BrintonD.K M Radtke