单项选择题
Apparent wind speed blowing across a ship under tow can be measured by a(n)（）.
A.barometer B.wind vane C.anemometer D.thermometer
单项选择题 Apparent time is based on（）.
单项选择题 Aphelion is the point where the Sun（）.
单项选择题 Any firefighting equipment that is carried in addition to the minimum required number on a ship must（）.
