XO-STAR电梯的厅外显示板通讯线数量为()根,其工作电源电压为()。
参考答案:4;DC30V
制度后评价的结果包含以下()几类。
A.整体有效
B.有效但需优化
C.存在重大缺陷
D.失效
An internet is a combination of networks connected by (1). When a datagram goes from a source to a (2), it will probably pass many (3) until it reaches the router attached to the destination network. A router receives a (4) from a network and passes it to another network. A router is usually attached to several networks. When it receives a packet, to which network should it pass the packet? The decision is based on optimization: Which of the available (5) is the optimum pathway?
空白(1)处应选择()
A.modems
B.routers
C.switcher
D.computers