A.A more efficient use of bandwidth can be achieved allowing many physical groups to use the same network infrastructure
B.Broadcast storms can be mitigated by decreasing the number of broadcast domains，thus increasing their size
C.A higher level of network security can be reached by separating sensitive data traffic from other network traffic
D.Port-based vlans increase switch-port use efficient，thanks to 802.1Q trunks
E.A more efficient use of bandwidth can be achieved allowing many logical networks to use the same network infrastructure
F.Broadcast storms can be mitigated by increasing the number of broadcast domains，thus reducing theirsize
G.VLANs make it easier for IT staff to configure new logical groups，because the vlans all belong to thesame broadcast domain