阿摩線上測驗
27. ____________ tells navigators how deep the sea depth is by sending signals from the
bottom of the ship hull to the sea bed.
(A) Echo sounder
(B) Automatic Identification System
(C) Global Positioning System
(D) Navtex
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統計： A(629), B(32), C(21), D(15), E(0) #3077034
統計： A(629), B(32), C(21), D(15), E(0) #3077034
