The private automobile has long played an important role in the US. In fact, it has become 小题1:___necessary and important part of the American life. In 1986, sixty-nine percent of American families owned 小题2:__least one car, and thirty-eight percent had 小题3:___than one. With the convenience of rapid transportation, workers don’t have to live near their workplace. This has encouraged the growth of the cities, 小题4:___it has also led to traffic problems.

For farm families the automobile is very helpful. It has made 小题5:___ possible for them to travel to town very often for business and for pleasure.

Family life has been affected in 小题6:___ways. The car helps to keep families together. However, when teenage children use the car, their parents can’t keep an eye on them. There is a great danger 小题7:____the driver has been drinking alcohol or taking drugs or breaking 小题8:_____ traffic laws.

Cars mean very much to Americans.

C++中，派生类继承了基类的全部数据成员和除 【14】 之外的全部函数成员。