单项选择题
The sea anchor shown as item number 14 will NOT（）.
A.check the liferaft's way B.keep the liferaft end on to the sea C.reduce the possibility of capsizing or broaching D.right the raft if it inflates inverted
单项选择题 The reference datum used in determining the heights of land features on most charts is（）.
单项选择题 The purpose of the “set” hand on an aneroid barometer is to（）.
单项选择题 The error in the measurement of the altitude of a celestial body，caused by refraction，increases as the（）.
