阅读下面的短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入适当的词或使用括号中所给词的适当形式填空，将答案写在答题卷相应题号后面的横线

Question

阅读下面的短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入适当的词或使用括号中所给词的适当形式填空，将答案写在答题卷相应题号后面的横线上。

Do you know how important cars are in people’s life in the United States? _____21______ a car most people feel that they are poor. And even if a person is poor he doesn’t really feel poor when he has a car.

There are three reasons _____22______ the car has become so popular in the United States. First of all the country is a large one and Americans like to move around in it. The car provides the most comfortable and _____23______ (cheap) form of transportation.

The second reason is _____24______ the United States has never really developed _____25______ efficient and inexpensive form of public transportation. Though there is a good system of air service （ 航空服务 ） it is so expensive that it can’t _____26______ (use) often.

Now the third reason and also the most important_____27______---the American spirit of independence. Americans don’t like to wait for a bus_____28______ a train. A car gives them the freedom to schedule _____29______ own time.

The gas shortage( 短缺 ) _____30______ (cause) a big problem for Americans since 1975. The real solution will have to be a new kind of car one that does not use so much gas.

Answer 1

26. be used     27. one     28. or          29. their    30.has caused