A. No steerageB. Answers backC. Answers all rightD. No ……

单项选择题This is a （）(罗兰).

A. compass
B. direction finder
C. loran
D. sextant

单项选择题Officers use sextants to observe （）.

A. stars
B. celestial bodies
C. the sun
D. the moon

单项选择题The telegraph is the（）(设备)that connects the engine room and the bridge.

A.gear
B.equipment
C.engine
D.sextant

单项选择题The captain wants to see the （）.

A. chief officer
B. second officer
C. third officer
D. carpenter

单项选择题Echo sounder sends a（） (无线电信号)from the bottom of the ship to the seabed.

A. radio signal
B. radio wave
C. signal
D. signal radio