登陆电子信箱，需要使用（）。 ["实名和密码","邮箱地址和密码","帐号和密码","手机号码和密码"]
《动车组列车服务质量规范》高铁快件集装件单节车厢装载的列车允许载重量为二等座车厢标记定员乘以（）千克。 ["50","60","70","80"]
由于变矩器本身具有的变速性能，对于同样的变速范围，可以（）变速箱的挡位数，简化变速箱结构。 ["最多","最少","减少","增加"]
按规定及时填写“三报一表”准确率达到（）以上，做好站车交接 ["百分之八十五","百分之九十","百分之九十五","百分之九十八"]
Refer to the exhibit. In this network， R1 has been configured to advertise a summary route， 192.168.0.0/22， to R2. R2 has been configured to advertise a summary route， 192.168.0.0/21， to R1. Both routers have been configured to remove the discard route （the route to null created when a summary route is configured） by setting the administrative distance of the discard route to 255.What will happen if R1 receives a packet destined to 192.168.3.1？（） ["The packet will loop between R1 and R2.","It is not possible to set the administrative distance on a summary to 255.","The packet will be forwarded to R2， where it will be routed to null0.","The packet will be dropped by R1， since there is no route to 192.168.3.1."]
ARP和反向ARP啥意思？
