Which two statements are true about voice VLANs？（） ["Voice VLANs are only used when connecting an IP phone and a host to distinct switch ports","Access ports that are configured with voice VLANs will always trust the CoS that is received from IP phones","Access ports that are configured with voice VLANs may or may not override the CoS value that is received from an IP phone","Voice VLANs are configured using the switchport voice vlan vlan-ID interface configuration command","Voice VLANs provide a trunking interface between an IP phone and an access port on a switch to allow traffic from multiple devices that are connected to the port","Enabling Voice VLAN on a switch port will automatically configure the port to trust the incoming CoS marking"]
邮政企业对哪些经营项目提供邮政普遍服务？
流感的特点是全身中毒症状较轻，发热与上呼吸道症状较重。
美的符号性
专业技术人员的学习过程是接受知识并在原有知识基础上不断创新的过程，这体现了专业技术人员学习能力的（）。 ["及时性","革新性","差异性","接受性和创造性的统一"]
书面语是在（）基础上建立起来的。
