多项选择题Which two statements are true regarding an Ethernet collision domain?()
A.If a switch is used, the collision domain includes all devices connected to the switch.
B.If a hub is used, the collision domain includes all devices connected to the hub.
C.If a hub is used, the collision domain is limited to each device and the hub.
D.If a switch is used, the collision domain is limited to each device and the switch.