烧结机密封装置主要有哪几种？
An orange flag showing a black circle and square is a（）. ["Signal indicating a course change","Distress signal","Signal of asking to communicate with another vessel","Signal indicating danger"]
高压开关柜应采用中置柜或（） ["环网柜","固定式柜","抽屉柜"]
客户交电话费时，应主动询问（） ["请在这里登记","请您先看一下宣传单","您好！请问您的电话号码？","这是您的发票"]
高低压配电系统：包括高压配电系统设备、变压器、低压配电系统设备、（） ["直流操作电源","蓄电池设备","自备发电机组","监控设备"]
烧结机的类型有哪些？
