an electrical machine investigating base to operate
electrical_junction is electrical_device. engine_starter is not electrical_device. electric_drill is electrical_device. engine_starter is electrical_device. endoscope is electrical_device. electrical_test_structure is not test_structure. single_device_test_structure is electrical_test_structure. milking_machine is electrical_device. electric_drill is not electrical_device. electrical_test_structure is test_structure.