单选题Directions:There are 10 questions in this part of the
test. Read the passage through. Then, go back and choose one suitable word or
phrase marked A, B, C, or D for each blank in the passage. Assuming that a constant travel-time budget, geographic
constraints and short-term infrastructure constraints persist as fundamental
features of global mobility, what long-term results can one expect? In
high-income regions, {{U}} {{U}} 1 {{/U}} {{/U}}North America,
our picture suggests that the share of traffic {{U}} {{U}} 2
{{/U}} {{/U}}Supplied by buses and automobiles will decline as high-speed
transport rises sharply. In developing countries, we {{U}} {{U}} 3
{{/U}} {{/U}}the strongest increase to be in the shares first for buses and
later for automobiles. Globally, these {{U}} {{U}} 4 {{/U}}
{{/U}}in bus and automobile transport are partially offsetting. In all regions,
the share of low-speed rail transport will probably continue its strongly
{{U}} {{U}} 5 {{/U}} {{/U}}decline. We expect
that throughout the period 1990-2050, the average North American will continue
to devote most of his or her 1.1-hour travel-time {{U}} {{U}} 6
{{/U}} {{/U}}to automobile travel. The very large demand for air travel (or
high-speed rail travel) that will be manifest in 2050 {{U}} {{U}}
7 {{/U}} {{/U}}to only 12 minutes per person a day; a little time goes a
long way in the air. In several developing regions, most travel {{U}}
{{U}} 8 {{/U}} {{/U}}in 2050 will still be devoted to nonmotorized
modes. Buses will persist whatever it is the primary form of motorized
transportation in developing countries for decades. {{U}} {{U}} 9
{{/U}} {{/U}}important air travel becomes, buses, automobiles and even
low-speed trains will surely go on serving vital functions. {{U}} {{U}}
10 {{/U}} {{/U}}of the super-rich already commute and shop in aircraft,
but average people will continue to spend most of their travel time on the
ground.