(填空)Cars are an important 36 of life in the United States.Without a car most people feel that they are poor.And 37 if a person is poor he doesn’t feel really poor when he has a car.There are three main reasons the car became so 38 in the United States.First of all the country is a huge one and Americans like to move 39 in it.The car provides the most comfortable and cheapest form. of transportation.40 a car people can go any place without spending a lot of money.The second reason cars are popular is the fact that the United States never developed 41 and inexpensive form. of public transportation.Long-distance trains have never been 42 common in the United States as they are in other parts of the worl D.Nowadays there is a good system of air-service provided by planes.But it is 43 expensive to be used frequently.The third reason is the most important one, though.The American spirit of independence is what really made cars popular.Americans don’t like to wait 44 a bus, or a train or even a plane.They don’t like to have to follow an exact schedule.A car gives them the freedom to schedule 45 time.And this is the freedom that Americans want most to have. 36.A.role B.part C.effect D.basis 37.A.ever B.still C.even D.quite 38.A.qualified B.increasing C.developing D.popular 39.A.around B.on C.along D.forth 40.A.Through B.Since C.With D.As 41.A.an interested B.an affected C.an efficient D.a satisfied 42.A.quite B.very C.too D.as 43.A.very B.so C.too D.as 44.A.for B.on C.beside D.about 45.A.their own B.theirs own C.their D.theirs