计算机网络除数据通信外,还有除______以外的三种功能。 Computer networks have three functions:___ other than data communications.
A.资源共享 ; resource sharing;###SXB###B.分布式信息处理; distributed information processing;###SXB###C.提高计算机系统可靠性与可用性; improving the reliability and availability of computer systems;###SXB###D.网络通信; network communications;