单选题 Communication networks can be classified in terms of their physical arrangement or (73) Three common (73) are the star, bus, and ring.

【正确答案】 B
【答案解析】[解析] 信息网络可以依据物理结构或拓扑结构进行分类，3个典型的拓扑结构是星型、总线型和环形。