单项选择题
The Address Resolution Protocol(ARP) is employed at ( ).Interface LayerB、Internetwork LayerC、Host-to-Host Transport LayerD、Application Layer
单项选择题 Virtual Private Networks(VPN) are networks deployed on a ( ) network infrastructure.areaD、wide area
单项选择题 You may keep the book ( ) you like.well asB、as long asC、as soon asD、as far as
单项选择题 Which of the following is not the e-commerce business models?
