A.k(3)=3 B.k(3)=1 C.k(3)= D.k(3)=
A.A相 B.B相 C.C相 D.B相和C相
A.ik1≠i≠ik0 B.ik1=i≠ik0 C.ik1≠i=ik0 D.ik1=i=ik0