英语四级完形填空含答案解释—ClozeTest34

　　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.