A.Sw+So=1 B.Sw-So=0 C.Sw+So=0.5 D.Sw-So=0.5
A.36.2106 B.32.6106 C.31.6206 D.31.6026
A.一组互相平行的直线; B.一组向外发散的射线; C.一组同心圆; D.越靠近排液道越密集;