Only rocket engines can be propelled to space because
A.they have high propulsion efficiency
B.they can generate very high thrust
C.these engines can work on several fuels
D.they are not air-breathing engines
Answer:D
Only rocket engines can be propelled to space because
A.they have high propulsion efficiency B.they can generate very high thrust C.these engines can work on several fuels D.they are not air-breathing engines