15.
A。医生怀疑是吸烟和咖啡引起的，但他没有这些嗜好，所以他只好说他没办法。
89
The
United States is full of automobiles(机动车) .There are still many families without cars. But some families have two
or 1 more. However, cars are used for 2 than pleasure. They are a 3 part of life.
Cars are 4 for business. They are driven to offices
and factories by workers who have no 5 way to get to their jobs. When salesmen
are sent to 6 parts of the city, they have to drive in
order to carry their products. Farmers have to drive into the city in order to
get home.
Sometimes small children must be driven to 7 . In some cities school buses are
used only when children live more than a mile from the school. When the
children are 8 young to walk that far, their mothers
take 9 to drive them to school One 10 drives on Mondays, taking her children
and the neighbours 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, with three or four men taking turns driving to the place 11 they work.
More car pools should be formed in order to put 12 motorcars on the road and to use less 13 . Parking is a great problem, and so
is the traffic in and around cities. 14 many cars are being driven,. Something
will have to be done 15 the use of cars.