An icebreaker displaying a flag hoist which consists of the code letters “WO” (Whiskey Oscar) is indicating that（）.

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 “（）”.

A.I am altering my course to starboard
B.I am altering my course to port
C.I am operating astern propulsion
D.My vessel is stopped and making no way through the water

单项选择题An example of an anchor which has a stock is a（）.

A.Bruce anchor
B.Dunn anchor
C.Hook anchor
D.Danforth anchor

单项选择题An example of a grade C product is（）.

A.naphtha，vm and p
B.tridecanol
C.cottonseed oil
D.camphor oil

单项选择题An example of a grade B product is（）.

A.piperyline
B.motor gasoline
C.kerosene
D.mineral spirits

单项选择题An entry of water，gas，oil，or other formation fluid into the wellbore is called a（）.

A.blowout
B.kick
C.gusher
D.flow