计算机软件分为哪些软件？各自的作用是什么？
Which of the following statements concerning IGMP are correct？（Choose all that apply.）（） ["With IGMPvl， queries are sent to a specific group","Hosts issuing IGMPvl requests will be correctly interpreted by IGMPv2 hosts due to backwardcompatibility","An IGMPv2 router will ignore IGMPv2 leave messages when IGMFVl hosts are present","With IGMFV2， a leave message is supported","An IGMPv2 host will send an IGMFVl report on an IGMFVl router","An IGMPv2 router can only allow IGMPv2 hosts to execute a join request"]
简述水轮发电机组是如何发电的？
沃克环流
确定矿物生成顺序的主要标志有哪些？
社会标签论
