[填空题]
In recent years, there has been a big increase in air travel
and many large airports have now reached the limit of the number of aircraft
movements they can handle. The problem is made worse by the size of many major
cities which prevents the extension of existing airports. Any new airports to be
built a long way from city centers will create communication problems and in
many countries there simply isn’t enough land for such developments.
Now a new proposal has been put forward which would help to relieve the
congestion (拥挤), as far as short flights are concerned. This involves the use of
smaller aircraft, carrying about 50 passengers, which only require a short take
- off or landing area and which make comparatively little noise because they are
propeller -driven (螺旋桨推进). Such aircraft could operate much nearer city centers,
say, on disused industrial sites, and give a good service to businessmen and
other travelers who are going between ce