空调系统通过调节空气量、温度、湿度和清洁度,为居住者提供舒适的环境。

单选题 Which of the following mediums used in actuators is not mentioned?( )

A、Electricity

B、Compressed air

C、Hydraulic oil

D、Spring

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单选题 The engine shown in the illustration is a .( )

A、four-stroke/cycle on the exhaust stroke

B、two-stroke/cycle on the exhaust stroke

C、four-stroke/cycle on the intake stroke

D、two-stroke/cycle on the intake stroke

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单选题 The word which"(underline word) refers to .( )

A、a linear motion

B、a 90° motion

C、a globe

D、a valve stem

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单选题 The combustion of fuel for the illustrated engine is initiated by____.( )

A、a spray of fuel into a turbulence combustion chamber

B、fuel sprayed into an energy cell

C、fuel injection provided by a unit injector

D、individual Bosch fuel pumps

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单选题 The engine cylinder illustrated is of the____.( )

A、dry liner type

B、wet liner type

C、type integrally machined in the block

D、integral wet liner type

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单选题 The word "the former" (underline word)means .( )

A、an electric motor

B、an actuator

C、a globe valve

D、a gate valve

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单选题 Which of the following statements is not true?( )

A、The valve actuators are used to open and close the valves.

B、Electric actuators can be stopped automatically when they move to the limit position.

C、The valve discs of the globe or gate valves can only be pushed or pulled in linear motion.

D、The disc of the butterfly valve can be turned 90° .

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单选题 The parts labeled "I and II", shown in the illustration are properly called the____.( )

A、intake and exhaust valves

B、scavenging poppets

C、fuel valves

D、exhaust valves

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填空题 空调系统通过调节空气量、温度、湿度和清洁度,为居住者提供舒适的环境。

填空题空调系统通过调节空气量、温度、湿度和清洁度,为居住者提供舒适的环境。