sentences: wood is an electrical / electrical matter insulator
docs: spark_plug_wire is insulated_wire. electrical_insulator is insulating_medium. insulated_wire is electrical_wire. metal is electrical_conductor. electrical_plug is electrical_conductor. power_cord is multi_conductor_insulated_wire. building_wire is insulated_wire. electrical_wire is electrical_conductor. insulator is material. electrical_plug is electrical_component.