短语词组短语signal l tracing instrument 信号故障探测仪signal tracing instrument 信号故障探测仪;信号寻纵器英语;信号寻纵器;翻译signal tracing test 信号寻迹测试signal tracing device 信号跟踪器signal tracing i trument 信号故障探测仪 返回 signal trace