其实蒙版和选区的原理相同，只不过蒙版不可以当作图形来编辑。
验收发电机时，检查其有无机械和电路故障，可采取（）试验。 ["负载","启动","空转","手动"]
苏轼称“元轻白俗”，“元”指诗人（）
根据《2000通则》的规定，以FOBST条件成交，买卖双方风险划分界限是在（）。 ["货交承运人","货物在目的港卸货后","货物在装运港越过船舷","装运码头"]
Your company has 250 client computers connected to the office LAN. The company has a pool of five public IP addresses. All client computers have dynamically assigned IP addresses. You need to provide all client computers with Internet access. What should you use？（） [" DHCP Relay Agent"," Routing Information Protocol （RIP）"," Internet Group Management Protocol （IGMP）"," Network Address Translation （NAT）\/Basic Firewall"]
举例说明教师应如何处理课堂上偶发事件？
