What are the answers
Dear Student,
Passenger airplanes mostly fly (a) at speeds less than that (b) of sound. Airplanes (c) which can fly (d) at greater speeds have been built. This is (e) because if they fly (f) at speeds greater (g) than the speed of sound, (h) the fuel consumption increases enormously.
Regards
Passenger airplanes mostly fly (a) at speeds less than that (b) of sound. Airplanes (c) which can fly (d) at greater speeds have been built. This is (e) because if they fly (f) at speeds greater (g) than the speed of sound, (h) the fuel consumption increases enormously.
Regards