21 Air Traffic Control started after the Grand Canyon crash in 1956

him. He can't see enough to be safe. Flight watch is an instrument intended to help him.

On a screen in front of the pilot, there will be a map of the【21】around the plane. The pilot's own【22】level or height and his own plane at the center of the【23】will show up. On the map any other planes in the airspace will【24】as spots of light with "tails" showing the direction of their light. The flight watch map is【25】for the other planes are not shown at their true【26】, but at their distances away in flying time. This【27】the problem of fast planes being too far away to be seen【28】likely to make contact in seconds and【29】planes that are close enough to be seen but so slow that there's no chance of【30】for, say, ten minutes.

The pilot will be able to see on the screen whether another plane's course conflicts with【31】. The screen will show him the flight number of the other plane, so he can contact air traffic control and ask them about the other plane’s course. Then he can take【32】action if necessary. The screen will show him whether his action puts him【33】from yet another aircraft.

Technically, the【34】will be quite complex. Computers will be necessary on the ground and【35】each aircraft to enable Flight watch to collect data about the plane courses and to calculate the distances between planes. But such small computers are now quite cheap, simple and reliable.

(36)

A．latitude

B．land

C．airspace

D．weather

ructure constraints persist as fundamental features of global mobility, what long-term results can one expect？ In high-income regions,【21】North America, our picture suggests that the share of traffic【22】supplied by buses and automobiles will decline as high-speed transport rises sharply. In developing countries, we【23】the strongest increase to be in the shares first for buses and later for automobiles. Globally, these【24】in bus and automobile transport are partially offsetting. In all regions, the share of low-speed rail transport will probably continue its strongly【25】decline.

We expect that throughout the period 1990～2050, the【26】North American will continue to devote most of his or her 1.1-hour travel-time【27】to automobile travel. The very large demand【28】air travel (or high-speed rail travel) that will be manifest in 2050【29】to only 12 minutes per person a day; a little time goes a long way in the air. In several developing regions, most travel【30】in 2050 will still be devoted to nonmotorized modes. Buses will persist【31】the primary form. of motorized transportation in developing countries for decades.【32】important air travel becomes, buses, automobiles and【33】low-speed trains will surely go on serving vital functions.【34】of the super-rich already commute and shop in aircraft, but average people will continue to spend most of their travel time on the【35】.

(21)

A．frankly

B．exceptionally

C．unfortunately

D．notably

ructure constraints persist as fundamental features of global mobility, what long-term results can one expect？ In high-income regions,【41】North America, our picture suggests that the share of traffic【42】supplied by buses and automobiles will decline as high-speed transport rises sharply. In developing countries, we【43】the strongest increase to be in the shares first for buses and later for automobiles. Globally, these【44】in bus and automobile transport are partially offsetting. In all regions, the share of lowspeed mil transport will probably continue its strongly【45】decline.

We expect that throughout the period 1990～2050, the【46】North American will continue to devote most of his or her 1.1-hour travel-time【47】to automobile travel. The very large demand【48】air travel (or high-speed mil travel) that will be manifest in 2050【49】to only 12 minutes per person a day; a little time goes a long way in the air. In several developing regions, most travel【50】in 2050 will still be devoted to nonmotorized modes. Buses will persist【51】the primary form. of motorized transportation in developing countries for decades.【52】important air travel becomes, buses, automobiles and【53】lowspeed trains will surely go on serving vital functions.【54】of the super-rich already commute and shop in aircraft, but average people will continue to spend most of their travel time on the【55】.

(21)

A．frankly

B．exceptionally

C．unfortunately

D．notably

nd the job they do—although there are certain people who do not believe that the police【22】have the power that they do.

What does a policeman actually do？ It is not【23】job to describe. After all, a policeman has a number of jobs in one. A policeman often has to control traffic. either【24】foot in the centre of a town, or in a police car on the roads. Indeed. in Britain, he might he in the Traffic Police and spend all, or a lot of, his time【25】up and down main roads and motorways. A traffic policeman has to help keep the traffic moving, stop【26】motorists and help when there is an accident.

A policeman has to help keep the【27】, too. If there is a fight or some other disturbance, we【28】the police to come and restore order. And they often have to deal with situation at great risk to their own【29】.

We expect the police to solve crimes, of course, so an ordinary policeman, even if he is not a detective(侦探) ,will often have to help【30】and arrest criminals.

And【31】do we call when there is an emergency—an air crash, a fire, a road accident. or a robbery？ We call the police.【32】a policeman has to be prepared to face any unpleasant emergency that may happen in the【33】world.

The police do an absolutely necessary job, they do it【34】well and I support them, but I do not envy policemen. I do not think that I could【35】do the job of a policeman.

(41)

A．dislike

B．join

C．appreciate

D．admire

rld Health Organization(WHO)has found that after studying【C1】______ countries— Austria, France and Switzerland. Long-term【C2】______ to exhaust fumes caused the premature death of 21 000 people【C3】______ respiratory and heart disease in the three countries,【C4】______ with nearly 10 000 deaths from accidents, WHO【C5】______ said last week. The report was prepared for【C6】______ to a conference of 70 environment and health ministers being organized by the United Nations agency in London. "The growing evidence【C7】______ air pollution is causing a major health burden adds to the effects of road traffic through noise, accidents and barriers【C8】______ cycling and walking, and we need to approach this head on," said Carlos Dora, a doctor with the WHOs European center for environment and health. "We are paying a huge【C9】______ for this excessive road transport; with our money and with our health. " One-third of pollution from fine particles which congest the lungs was【C10】______ by motor vehicles, rising to one-half in cities, the WHO found.

【C1】

A．typical

B．European

C．industrial

D．Asian