He is a professional electric technician 他是专业的电工技师。
2.
An appropriate power plug has to be attached to the machine by electric technicians . power plug has to be connected to a grounded receptacle 电源插头应用具有电气专门知识的人来安装。电源插头必须连接到接地插座上。
3.
Repair and maintenance works of electrical components shall be conducted by qualified electric technicians or under the audit and guidance of specially skilled personnel 有关缝纫机的电气方面的修理、维修应由有资格的电气技术人员或专家的监督和指导下进行。
