The burning of the fuel adds more heat to the air charge， causing it to expand and force the engine piston to do work on the crankshaftWhat does “it” mean in this sentence?（）
A: the burning
B: the fuel
C: the air charge
D: the engine pisto
A: the burning
B: the fuel
C: the air charge
D: the engine pisto
举一反三
- The burning of the fuel adds more heat to the air charge， causing it to expand and force the engine piston to do work on the crankshaftWhat does “it” mean in this sentence?（）
- By burning its fuel, the engine makes the automobile travel on road
- Burning fuel with a high sulfur content in a diesel engine will （） A: increase thermal efficiency B: cause clogging of the fuel system C: increase the ability of the engine to start in cold weather D: produce corrosion in the cylinder and exhaust system at low load
- As fuel is burned in the engine, about one-third of the heat energy in the fuel is converted into power.
- In an automobile engine, the vaporized fuel is mixed with air, compressed in the cylinder and by a spark. A: blazed B: flamed C: ignited D: exploded