单项选择题
Which of the following is the BEST network device to allow multiple network connections to beterminated in one spot?（）
A. A patch panel B. A 66 block C. A smart jack D. A cross connect
单项选择题 Which of the following uses TCP?（）
单项选择题 Data encryption and decryption occurs at which layer of the OSI model?（）
单项选择题 Which of the following is the MOST accurate description of a L2/L3 switch?（）
