A.synchronizes FIFO， PQ， CQ， and MDRR， with WFQ， CBWFQ， and LLQ
B.enables strict priority queuing for voice traffic， and weighted round robin queuing for data traffic
C.enables low latency queuing to ensure that voice traffic receives priority treatment
D.enforces a trust boundary on switch access ports and uplinks/downlinks 
E.modifies queue sizes as well as queue weights where required 
F.adjusts link speeds to adapt to QoS needs

A.class-based policing is configured using the Modular QoS command-line （MQC）
B.only the Frame Relay traffic-shaping （FRTS） mechanism can interact with a Frame Relay network， adapting to indications of Layer2 congestion in the WAN links
C.Distributed Traffic Shaping （DTS） is configured with the police command under the policy map configuration
D.both Frame Relay traffic shaping （FRTS） and virtual IP （VIP）-based Distributed Traffic Shaping （DTS） have the ability to mark traffic