For an aircraft to fly continuously and steadily in the sky, the most basic conditions should be met are: ____.
A. Sufficient lift
B. Sufficient power
C. Good piloting technique
D. Good stability and maneuverability
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The main characteristics of a piston engines include: ____.
A. More efficient when flying at low speed
B. Are direct reaction engines
C. When the aircraft's flight speed exceeds 700-800 kilometers per hour, the propulsion efficiency will also drop sharply
D. Widely used in some small and low-speed aircraft
The core components of the turbojet include: ____.
A. Intake duct
B. Compressor
Combustion chamber
D. Turbine
The characteristics of ramjet includes: ____.
A. Complex structure
B. Inefficient when the aircraft is flying at low speed
C. Good intake and compression performance when the aircraft is flying at low speed
D. Usually used in combination with other types of engines
The power source of electric power device mainly comes from: ____.
A. Solar cell
Battery
C. Wind energy battery
D. Fuel cell
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