轮机英语试题二十一

试题二十一

一、单项选择题：

1.In a two-stroke engine the camshaft rotates at ______the engine rotational speed.

A. half

B. twice

C. the same speed as

D. four times

2.______ pistons have low inertia and high coefficient of thermal expansion.

A. Cast iron

B. Cast steel

C. Forged steel

D. Aluminum

3.______ rods are not in the proper condition so that too much fuel is supplied to the

corresponding cylinder.

A. Piston

B. Sounding

C. Regulating

D. Connecting

4.The time between injection and ignition of the fuel is known as ______.

A. turbulence lag

B. after burning ratio

C. pre-ignition lag

D. ignition delay

5.______ is arranged for cleaning the lubricating oil in the system and clean oil can be

provided from a storage tank.

A. A filter

B. A centrifuge

C. A distiller

D. A generator

6.Impurities in the fuel oil will affect the operation of the engine, which has ______the use of

separator and some other devices.

A. brought about

B. caused for

C. resulted from

D. led

7.Diesel engine jacket water is used in the distillation process as the ______.

A. coolant for the distillate

B. coolant for the brine cooler

C. means of heating the feedwater

D. primary means of producing a vacuum within the distiller

8.According to the way the energy of the exhaust gases is utilized, pressure-charging can be

divided into two main systems, namely, the constant-pressure system and ______.

A. the pulse-phase system

B. the pulse Doppler system

C. the pulse system

D. the pulse interval

9.Two-stroke engines invariably have ______ to admit air when uncovered by the descending

piston.

A. inlet ports

B. outlet ports

C. inlet valves

D. exhaust valves

10. A sealing arrangement is provided at ______ of the tail-shaft with the propeller and cone

completing the arrangement.

A. both ends

B. neither end

C. the outboard end

D. either end

11.Some vessels are equipped with a water lubricated stern tube. When at sea, operating under

normal conditions, the water service valve from the ship's saltwater system to the bearing should be______.

A. closed, and no leakage permitted across the shaft packing

B. closed, and only slight leakage permitted across the shaft packing

C. opened, and no leakage permitted across the shaft packing

D. opened, and only slight leakage permitted across the shaft packing

12.______ the repair in so short a time is unknown to us.

A. How they finished

B. How did they finished

C. That how they finished

D. That how did they finished