单项选择题
The expression FIRST MAGNITUDE is usually used to refer only to bodies of magnitude（）.
A.1.5 and greater B.1.25 and greater C.1.0 and greater D.0.5 and greater
单项选择题 The expression DROP ANCHOR means（）.
单项选择题 The best method to stop a vessel from dragging anchor in a sand bottom is to（）.
单项选择题 PAN-PAN repeated three times over the radiotelephone indicates which type of message will follow?（）
