So   1   do people travel those distances that are too far to walk? They use public transportation. If you ride the subway or bus   2  you live, you can appreciate some of the benefits of public transportation. With many people           3       (share) one bus or train, there is less traffic and, more  4   （importance）, less pollution.
Which of the types of mass transit   5   (describe) below are you familiar with? If a regular bus can hold       dozens of people, imagine what a bus   6            (two) the size can hold! In Great Britain, there are many buses that are known as double-deckers (cars with two floors).
Buses in Haiti are often very crowded. It’s not   7   (common) for passengers to actually sit on the rooftops. Buses are sometimes called “tap-taps”, because the    8    (ride) on the roof tap（敲击）when they want to be dropped off.
Many large cities around the world take advantage of the space beneath the streets and run underground trains. People in Paris, Mexico City and Tokyo may use the subway system to get to school, to work, or to visit friends in other    9               (neighbor). Both the Japanese and French have developed       High-speed trains to link various cities. While electric trains in North America average 130 kph, the French TGV (high-speed-train) is the world’s fastest,  10  (average) over 270 kph!