词汇	extremely low frequecny
释义	extremely low frequecny elf至低频3~30Hz
随便看	equivalent features equivalent fetch equivalent fetch length equivalent fiber bundle in g equivalent fibre bundle equivalent filter realization equivalent finished unit equivalent finished unit costs equivalent finite-element method equivalent finite element stress equivalent fire endurance equivalent fire load Equivalent fire-resistance time equivalent fire severity Equivalent First Cost equivalent flat plate area equivalent flaw diameter Equivalent flexibility equivalent flexural rigidity equivalent flocculation equivalent flow equivalent flow coefficient equivalent flowing resistance method equivalent fluid equivalent flux path