第三部分语法填空 (共2篇，20小题；每小题1. 5分，满分30分)
语法填空（一）阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空，并将答案填写在答题卷标号为46~55的相应位置上。
Cars are too expensive for many people around the world to own. Not only that, many cities are already full of traffic, and many country areas have rough roads.
So   46          do people travel those distances that are too far to walk? They use public transportation. If you ride the subway or bus   47            you live, you can appreciate some of the benefits of public transportation. With many people   48            (share) one bus or train, there is less traffic and, more   49              （importance）, less pollution.
Which of the types of mass transit   50           (describe) below are you familiar with? If a regular bus can hold       dozens of people, imagine what a bus        51             (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   52            (common)         for passengers to actually sit on the rooftops. Buses are sometimes called “tap-taps”, because the   53             (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             54         (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,         55               (average) over 270 kph!