单项选择题
A.32768: 11-22-33-44-55-66
B.32768: 22-33-44-55-66-77
C.32769: 11-22-33-44-55-65
D.32769: 22-33-44-55-66-78
多项选择题 Which two protocols are used by bridges and/or switches to prevent loops in a layer 2 network? （）
单项选择题 What is the function of the command switchport trunk native vlan 999 on a switch?（）
单项选择题 Refer to the exhibit.Switch-1 needs to send data to a host with a MAC address of 00b0.d056.efa4.What will Switch-1 do with this data?（）