In the context of MPLS，what is the correct action to be performed when an aggregate label is received ？（） ["It adds the VPN label into the top label in the MPLS label stack","It replaces the top label in the MPLS label stack with a VPN label and propagates","It replaces the bottom label in the MPLS label stack with a VPN label and propagates","It removes the top label in the MPLS label stack and does a Layer 3 lookup on underlying IP packets","None of above"]
运动饮料的三种类型及其特点。
已知下表所提供的资料，计算并回答问题：
可编程控器中存储器有（） ["系统程序存储器","备用存储器","读写存储器","用户程序存储器"]
下列属于良好的生活方式中合理安排膳食的是（） ["节食","共餐","睡前不饱食","吃好早餐、节制午餐、保证晚餐"]
角色学习
