题目内容：
共用题干Traffic in Our Cities
The volume of traffic in many cities in the world today continues to expand.This causes many problems,
including serious air pollution,lengthy delays,and the greater risk___________(51)accidents.Clearly,
something must be done,but it is often difficult to persuade people to___________(52)their habits and
leave their cars at home.
One possible___________(53)is to make it more expensive for people to use their cars by__________(54)
charges for parking and bringing in tougher fines for anyone who__________(55)the law. In addition,drivers
could be_(56)to pay for using particular routes at different times of the day. This system,
___________(57) as"road pricing",is already being introduced in a_(58)of cities,using a
special electronic card___________(59)to the windscreen of the car.
Another way of___________(60)with the problem is to provide cheap parking on the___________(61)of
the city,and strictly control the number of vehicles allowed into the centre.Drivers and their passengers then
use a special bus__________(62)for the final stage of their journey.
Of course,the most important___________(63)is to provide good public transport. However,to get
people to give___________(64)the comfort of their cars,public transport must be felt to be reliable,con-
venient and comfortable,with fares___________(65)at an acceptable level.
_________(57)
A:designed
B:known
C:seen
D:called
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