单选题Which of the following conditions can cause below normal air pressure in the intake manifold of a turbocharged diesel engine?（）A Excessive piston blow-by to the manifoldB Insufficient cooling water flowC Accumulated water in the air boxesD Clogged air

In an operating diesel engine, which of the following conditions is an indication of a leaking air starting valve?

A.Noise coming from that air starting valve

B.Continuous operation of the starting air compressor

C.Zero air pressure in the air starting system

D.Overheated starting air pipe to the cylinder head

According to this passage, which of the following statements is true?

A.In boiler and machinery spaces, there is the air conditioning.

B.In the boiler rooms the requirement of air volume should meet 25-50% of combustion requirement.

C.To maintain the comfort zone in the separate control room the air conditioning plant should be fitted.

D.The comfort conditions can be maintained in the engine room all the time.

Which of the listed conditions can be considered as the single greatest cause of accidents?

A.Speed

B.Excessive knowledge or skill

C.Human error

D.Excitement

题干材料：Due to the large amount of heat picked up by the air in boiler and engine rooms, it would be impracticable to maintain ambient conditions within the comfort zone by air conditioning or any other means. The normal practice is to provide copious mechanical ventilation; in boiler rooms, the quantity is equated to the combustion requirements, while in a motor ship engine room the supply may be 25-50% in excess of the requirements of the engines.

The axial flow fan is particularly suited to handle these large air volumes at the moderate pressures required, while of course the “straight-through” flow feature places it at an advantage over the centrifugal fan.

The increasing adoption of automation, with the provision of a separate control room makes less significant the fact that comfort conditions cannot be maintained in the engine room all the time.

问题：Which of the following devices should be taken to maintain ambient conditions of the boiler and machinery space?

A.air compressor

B.air cooler

C.air-conditioning plant

D.mechanical ventilation plant

In a motor vessel, the air quantity which the engine room need is_______ of the requirements of the engines.A.less than 25-50%

B.more than 125-150%

C.more than 25-50%

D.less than 125-150%

According to this passage, which of the following statements is true?

A.In boiler and machinery spaces, there is the air conditioning

B.In the boiler rooms the requirement of air volume should meet 25-50% of combustion requirement

C.To maintain the comfort zone in the separate control room the air conditioning plant should be fitted

D.The comfort conditions can be maintained in the engine room all the time

At the middle pressure and large air quantity,_________ is more suitable.A.an axial flow fan

B.a radial flow blower

C.a centrifugal fan

D.an auxiliary blower

请帮忙给出每个问题的正确答案和分析，谢谢！

If the suction pressure at the refrigeration compressor is below normal, the cause can be

A.refrigerant overcharge

B.overfeeding by the expansion valve

C.a restricted suction strainer

D.due to short cycling of the compress