阿摩線上測驗
34. What is the fundamental frequency of the signal of whistle
stipulated by COLREGS?
(A) Within the range 50~500 Hz.
(B) Within the range 60~600 Hz.
(C) Within the range 70~700 Hz.
(D) Within the range 80~800 Hz.
答案：登入後查看
統計： A(80), B(98), C(219), D(37), E(0) #1312623
統計： A(80), B(98), C(219), D(37), E(0) #1312623
