航海英語海洋學基本知識單項選擇題每日一練(2019.01.11)

來源：考試資料網

1 In modern fathometers the sonic or ultrasonic sound waves are produced electrically by means of a(n)（）.

2 The cold ocean current which meets the warm Gulf Stream between latitudes 40°and 43°N to form the cold wall is called the（）.

3 The apparent wind can be zero when the true wind is from（）.

4 Steam fog is most likely to occur on the Mississippi and Ohio Rivers in（）.

5 A backlash below a lock is defined as（）.