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單項(xiàng)選擇題

It is during （） that work energy is being put into the engine; during the other 3 strokes of the piston, the engine is having to do the work.

A.the suction stroke
B.the compression stroke
C.the expansion stroke
D.the exhaust stroke

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單項(xiàng)選擇題

In the suction stroke, the crankshaft is rotating clockwise and the piston is moving （） the cylinderThe inlet valve is （） and a fresh charge of air is being drawn or pushed into the cylinder by the turbocharger.

A.up；opened
B.down；open
C.up；closed
D.down；closed

單項(xiàng)選擇題

The four-stroke cycle is so called because it takes （） to complete the processes needed to convert the energy in the fuel into work.

A.two strokes of the piston
B.four strokes of the piston
C.one revolution of the crankshaft
D.four revolutions of the crankshaft