单项选择题
Which layer of the OSI reference model uses flow control, sequencing, and acknowledgements to ensure that reliable networking occurs?（）
A. data link B. network C. transport D. presentation E. physical
单项选择题 Which layer of the OSI reference model uses the hardware address of a device to ensure message delivery to the proper host on a LAN?（）
单项选择题 Which option is a valid IPv6 address?（）
单项选择题 What is known as "one-to-nearest" addressing in IPv6?（）
