单项选择题
An aneroid barometer on a boat should always be（）.
A.located in an air-conditioned area B.mounted in the passenger compartment C.protected by a collision bulkhead D.permanently mounted
单项选择题 An anchored vessel is servicing an aid to navigation and is restricted in her ability to maneuver. Which lights will she show? （）
单项选择题 An all-round flashing yellow light may be exhibited by a(n)（）.
单项选择题 An airplane should NOT send which signal in reply to a surface craft?（）
