单项选择题
Radar is not only to obtain（）,but also to measure their distance away from you.
A.brightness of obtain B.color of targets C.shape of targets D.bearing of objects
单项选择题 The anchor was then（）and the siren sounded.
单项选择题 Are there many（）and warehouses in the port?
单项选择题 The quartermasters（）steer the ship and help the officer keep lookout.
