What is valid reason for a switch to deny port access to new devices when port security is enabled?（） [" The denied MAC addresses have already been learned or confgured on another secure interface in the same VLAN."," The denied MAC address are statically configured on the port."," The minimum MAC threshold has been reached."," The absolute aging times for the denied MAC addresses have expired."]
塑料注射成型工艺中保压的作用是防止（）。
受益人是信托中享有信托权益者，可以是自然人，也可以是法人或其他组织，其法律身份包括 （）。 ["受托人","委托人","债权人","第三人"]
What are two uRPF working modes？（） ["express mode","safe mode","loose mode","strict mode","tight mode"]
自控飞机的运转形式是（）。 ["绕水平轴转动；","往复摆动；","沿架空轨道运行；","回转和升降。"]
“金融约束”理论
