单选题When the vessel on the full speed ahead, if full astern immediately （） the main engine start astern and fuel injection.A after the thrust power is zeroB after the torsion is zeroC surpass the critical point on the water turbo phaseD after the speed is

Full speed astern!

A.后退三！

B.后退二！

C.后退一 ！

D.中速后退！

A large vessel is equipped with a controllable pitch propeller. Which statement is TRUE?

A.When dead in the water，it is often difficult to find the neutral position and slight headway or sternway may result

B.When going directly from full ahead to full astern，there is complete steering control

C.When the vessel has headway and the propeller is in neutral，there is no effect on rudder control

D.When maneuvering in port，full ahead or astern power can usually be obtained without changing shaft RPM

My ship’s engine responds well to telegraph orders and takes about 80 seconds to reverse from full speed ahead to full speed astern. This sentence ______.

A.indicates the engine’s particulars

B.tells the engine’s function

C.shows the engine’s type

D.refers to the engine’s information

It takes about 12 seconds to reverse______full speed ahead______full speed astern．

A.at，to

B.to，from

C.from，to

D.at，from

On a vessel with a single propeller，transverse force has the most effect on the vessel when the engine is put ______．

A.full ahead

B.full astern

C.half ahead

D.slow astern

The order“______” means “Maximum maneuvering engine revolution for ahead propulsion.”

A.Full Ahead

B.Half Ahead

C.Full Astern

D.Half Astern

Please tell me ______ to reverse your engine from full ahead to full astern．

A.How length will it take

B.How long it will take

C.How long will it get

D.How much hours it will take

紧急后退三。

A.Full astern！

B.Double full astern！

C.Emergency full astern！

D.Emergency three astern！

“Full speed ahead” and “Full speed astern” are ______ given by the officers or the pilots.

A.sailing orders

B.speed orders

C.wheel orders

D.telegraph orders