问题 选择题 已知复数z=1-3i3+i,.z是z的共轭复数,则z•.z等于( )A.16B.4C.1D.116 答案 因为z=1-3i3+i=(1-3i)(3-i)(3+i)(3-i)=-4i4=-i,所以z•.z=-i2=1.故选C.