The United States is full ________ automobiles. There are still many families ________ cars, but some families have two or even more. However, cars are used for more than pleasure. They are a necessary part ________ life. Cars are used ________ business. They are driven ________ offices and factories ________ workers who have no other way to get ________ their jobs. When salesmen are sent ________ different parts of the city, they have to drive in order to carry their products. Farmers have to drive ________ the city in order to get supplies. Sometimes small children must be driven to school. In some cities school buses are used only when children live more than a mile ________ the school. When the children are too young to walk that far, their mothers take turns driving them to school. One mother drives on Mondays, taking her own children and the neighbors’ children as well. Another mother drives on Tuesdays, another on Wednesdays, and so on. This is called forming a car pool. Men also form car pools, ________ three or four men taking turns driving to the place where they all work. More car pools should be formed in order to put fewer automobiles ________ the road and to use less gasoline. Parking is a great problem, and so is the traffic ________ and ________ cities. Too many cars are being driven. Something will have to be done ________ the use of cars.