Now a new 39 has been put forward which would help to 40_ the congestion, as far as short flights are concerned. This 41 the use of smaller aircraft, carrying about 50 passengers, which only require a short take-off or landing area and which make 42_ little noise because they are propeller-driven.

　　The main problem 43 is the question of noise. 44 __________ _____________ ___ _ , that any government can expect to find considerable resistance to building new airports in towns, even though these short-range small planes are relatively quiet. 45______________ ______ if they can have the conveniences of an airport near the city center. In the end, 46______________ ______