单选题

The OS! (68) model, sometimes also called ISO or 7 layers reference model for communication, has been developed by the International Standards Organization in early 1980' s.
A. referent B. reference C. referance D. refering
【正确答案】 B
【答案解析】[解析] OSI参考模型，有时也称做ISO或者7层通信参考模型，是在20世纪80年代初由国际标准化组织所认定的。