Context changes due to page switching with a cross-page wire or selection change take place in the central components.
上下文根据页面切换而变化，此时在中心组件中会产生跨页面连接和选择变更。
2
Install electromechanical, analog and digital trunking systems, circuits and equipment in telecommunications central offices and switching centres.
在电信中心办公室和交换中心安装工机电，模拟和数字集群系统，电路和设备。
3
Beijing dismantling air-conditioning, professional air conditioning mechanic, supply air conditioning, fission air conditioning, central air conditioning switching, repair, and snow of clean, protect.