每半年检查维护项目有哪些？
When planning for VoWLAN capacity during a site survey， how many simultaneous calls can beestimated per 5 GHz channel？（） ["7","14","20","30"]
10岁男孩，一年来时有尿频、尿急、排尿痛和排尿困难，尿流常突然中断，改变体位后又能继续排尿，应首先考虑（） ["急性膀胱炎","泌尿系结核","尿道狭窄","前列腺炎","膀胱结石"]
Your network consists of a single Active Directory domain.You have a domain controller named Server1 that runs Windows Server 2003 Service Pack 2 (SP2).The DNS service is installed on Server1. Server1 contains only Active Directory-integrated zones. Zone transfers are disabled for all zones.You need to back up the DNS zones on Server1. What should you do? （） ["From a command prompt, run Nslookup.exe. ","From Windows Backup, back up the system state. ","From Windows Backup, back up %SystemRoot%\\System32\\DNS. ","From the DNS snap-in, right-click Server1 and then click Export List."]
经典性条件作用规律包括（）。 ["习得","消退","泛化","强化","分化"]
空城计
