VOIP is being implemented in the network and you need to assess the need for QoS. Which of thefollowing network problems would indicate a need to implement QoS features？（） ["Mis-routed packets","Excess jitter","Delay of critical traffic","Packet loss due to congestion","Data link layer broadcast storms","FTP connections unsuccessful"]
18个月的婴儿能搭积木6～7块，逐页翻书，用蜡笔乱涂。
关于路由器的描述，错误的是（）。 ["路由器的转发策略称为路由选择","路由器的软件主要由路由器的IOS操作系统组成","路由器是网络的主要瓶颈","路由器的基本功能是路径选择和数据转发"]
如果要在网页中插入插件，最常用的操作应（）进行设置。 ["点击标志1","点击标志2","点击标志3","点击标志4"]
发泡陶瓷保温板的施工操作中，挤塑板安装的表面平整允许偏差为（）。 ["A.4mm ","B.1mm ","C.2mm ","D.3mm"]
怎样预防脚手架坍塌事故？
