多项选择题
Although TCP segments differ from UDP segments, they both contain some common fields. What two segments do they share in common?（）
A. source address B. options C. sequence number D. sources E. destination port F. checksum
多项选择题 Which of the following protocols utilize TCP?（）
单项选择题 Which one of the following protocols uses both UDP and TCP ports for the transport layer operation?（）
多项选择题 Which of the following protocols utilize UDP as the layer 4 transport mechanism?（）
