由于亚丁湾海域索马里海盗活动日益猖獗，一些航运公司被迫改变航线，使得苏伊士运河收入大幅度减少。下列关于苏伊士运河的叙述正确的是

A．沟通了地中海和大西洋

B．沟通了地中海和黑海

C．沟通了大西洋和太平洋

D．沟通了地中海和红海

Communication networks can be classified in terms of their physical arrangement or (74) Three common (74) are the star, bus, and ting.

A．structures

B．topologies

C．protocols

D．frames