A propeller of 5~65m in diameter, having a mean pitch of 4~8

Propeller pitch speed minus ship speed divided by the propeller pitch speed is termed ___.

A.apparent slip

B.true slip

C.pitch

D.propulsive efficiency

Compared to a constant pitch propeller, a controllable pitch propeller

A.more efficiently uses available engine power

B.operates at a lower efficiency at a fixed speed

C.produces the same torque at lower engine power

D.develops its rated power at a lower speed

What does the author mean by “most people are literally having a ZZZ” (Lines 2-3, Paragraph 5)?

A They are getting impatient.

B They are noisily dozing off.

C They are feeling humiliated.

D They are busy with word puzzles.

_______ he has enough money to buy the house， it doesn‘t mean he’s going to do so. A. Grant B. Granted that C. Having Granted that D. Grant that

A controllable pitch propeller on a diesel driven vessel eliminates the need for

A.friction clutches

B.disconnect clutches

C.reversing gears

D.reduction gears

_____ of the controllable pitch propeller enables the blades to be moved to change the pitch angle

A.An external mechanism

B.An internal mechanism

C.An interlock device

D.A hunting gear system

X线平均波长(λmean)与最短波长(λmean)的关系是

A.λmean=3λmin

B.λmean=5λmin

C.λmean=2λmin

D.λmean=5λmin

E.λmean=λmin

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