单项选择题
A client wants to improve the wireless coverage on the third floor of their house. The wireless router is located in the basement and there is no easy way to run a cable to the third floor. Which of the following devices should be installed to extend the wireless coverage to cover the entire third floor without running cables?（）
A.Switch B.Router C.Repeater D.Bridge
单项选择题 Which of the following regulates the amount of network traffic a single node receives in a servercluster?（）
单项选择题 A standard installation for wireless will use which of the following antenna types?（）
单项选择题 Which of the following protocols requests membership to a multicast group?（）
