单项选择题 Which of the following wireless technologies can support the GREATEST distance on either 2.4GHz or 5GHz frequencies?（）

单项选择题 Which of the following protocols can be found at the application layer?（）

单项选择题 The network administrator has just finished installing a new 10/100/1000 switch, but receives reports from the server administrator that servers connected to the new switch seem to be experiencing slow LAN connections. The network administrator checks the port connecting the new switch to the core switch and sees the following information: Which of the following is the MOST likely cause of the slow connections?（）