词汇	duplex tube
释义	duplex tube 孪生管,复合管,双管
随便看	directional drop point directional duality principle directional duration immunization directional dynamics directional earth leakage relay directional earth-leakage relay directional echo sounding directional echo-sounding directional effect directional element directional elements directional emissivity directional emittance directional emitter directional energy gain directional enrollment directional entropy directional error Directional errors directionalet directional etching directional-eutectoid directional evacuation directional exit sig directional exit sign