单项选择题
An icebreaker displaying a flag hoist which consists of the code letters “WO” (Whiskey Oscar) is indicating that（）.
A.icebreaker support is finished B.icebreaker support is commencing C.the icebreaker is icebound D.the icebreaker is beset
单项选择题 An icebreaker assisting a vessel through an ice field would display a visual signal consisting of the code letter “E” (Echo) to signify that “（）”.
单项选择题 An example of an anchor which has a stock is a（）.
单项选择题 An example of a grade C product is（）.
