A.1S B.2S C.3S D.5S
A.182.37.255.6 B.54.77.182.282 C.184.34.20.78 D.233.68.0.1000
A.90% B.92% C.95% D.98%
A.点对点”拓扑结构 B.多点共线的模式 C.“星型”拓扑结构
A.1/2 B.1/4 C.1/8 D.1/10
