单项选择题
Radar reflectors are required for（）.
A.all fishing vessels over 39 feet in length B.sail-propelled fishing vessels C.all fishing vessels of less than 200 GT D.wooden hull fishing vessels with a poor radar echo
单项选择题 Radar makes it possible and much safer for us to sail（）.
单项选择题 Radar beacons are transmitters designed to produce a（）on the screens of ship’s radar sets.
单项选择题 Proper use shall be made（）radar equipment.
