单项选择题
At the master gyrocompass，the compass card is attached to the（）.
A.spider element B.sensitive element C.link arm D.pickup transformer
单项选择题 At sea，we can use（）to fix the ship’s position.
单项选择题 Assumption shall（）on the basis of scanty information especially scanty radar information.
单项选择题 As a vessel changes course to starboard，the compass card in a magnetic compass（）.
