echo-sounder

n instrument used for determining the depth of sth underneath a ship by measuring the time taken for sound waves to be echoed back from it 回声探测器.

eaves, eavesdrop, eavesdropper, ebb, ebb tide, ebony, ebullience, ebullient, ebulliently, EC, eccentric, eccentrically, eccentricity, ecclesiastic, ecclesiastical, ecclesiastically, ECG, echelon, echo, echo-location, echo-sounding, Eckhard Hess, eclair, eclat, eclectic, eclectically, eclecticism, eclipse, eco-, ecological, ecologically, ecologist, ecology, Econ, economic, economical, economically, economics, economist, economize,