属于市场机制的基本构成要素的是（）。 ["供求机制","社会保障机制","分配机制","宏观调控机制"]
简述品德与道德的关系。
An IP phone connects a user to a switch as shown below： Based on the diagram shown above， which statement is true about the voice traffic coming to theswitch access port that is connected to the IP phone？（） ["A PC connected to a switch port via an IP phone is unaware of the presence of the phone","The traffic on the voice VLAN must be tagged with 802.1p encapsulation in order to coexist onthe same LAN segment with a PC","To improve the quality of the voice traffic， no other devices should be attached to the IP phone","The voice VLAN must be configured as a native VLAN on the switch","A PC connected to a switch port via an IP phone must support a trunking encapsulatio"]
（）不属于按交换方式分类的网络。 ["电路交换","局域网","报文交换","分组交换"]
假设在Internet上的一个B类地址具有子网掩码255.255.240.0，问该网络中可同时接入的最大主机数是多少？
动物性蛋白质饲料的营养特点：（相对植物性）？
