We were at the end of the hall and could not hear the speech because his vioce was ______ soft to be heard. A: more B: so C: too D: much

网络管理员需要在交换机上配置端口安全。哪两种说法是正确的？（） A: 动态端口不能应用的端口安全 B: in the vioce vlan C: 保存在running configuratin D: EtherChannels 不能应用端口安全 E: 自动学习mac地址可以学到所设置的最大数量