单项选择题
A.the suction stroke
B.the compression stroke
C.the expansion stroke
D.the exhaust stroke
单项选择题 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.
单项选择题 The four-stroke cycle is so called because it takes () to complete the processes needed to convert the energy in the fuel into work.
单项选择题 The purpose of the skirt or trunk in four-stroke cycle engines is to act in a similar manner to a ().