题目内容：
Before the 20th century the horse provided day to day transportation in the United States.Trains were used only for long-distance transportation. Today the car is the most popolar 1 of transportation in all of the United States.It has completely 2 the horse as a means of everyday transportation.Americans use their car for 3 90 percent of all personal 4 .
Most Americans are able to 5 cars.The average price of a 6 made car was ,050 in 1950, 740 in 1960 and up to , 750 7 1975.During this period American car manufacturers set about 8 their products and work efficiency.
As a result, the yearly income of the 9 family increased from 1950 to 1975 10 than the price of cars.For this reason 11 a new car takes a smaller 12 of a family's total earnings today.
In 1951 13 it took 8.1 months of an average family's 14 to buy a new car.In 1962 a new car 15 8.3 of a family's annual earnings.By 1975 it only took 4.75 16 income.In addition, the 1975 cars were technically 17 to models from previous years.
The 18 of the automobile extends throughout the economy 19 the car is so important to Americans.Americans spend more money to 20 their cars running than on any other item.
阅读短文回答题。
1.填入正确答案 A．kinds
B．means
C．mean
D．types
参考答案：
答案解析：