问题: [单选,材料题] taken 回答下面的题目:Traffic in Uur CitiesTile volume of traffic in many cities in the world today continuesto expand.This causes many problems,including serious air pollution,lengthydelays,and the greater risk__________ (51)accidents.Clearly,something must be done,but it is often difficult to persuade people to__________ (52)theirhabits and leave their cars at home.One possible__________ (53)is to make it more expensive for peopleto use their cars by__________ (54)charges for parking and__________ (55)tougherfines for anyone who__________ (56)the law.In addition,drivers could be required to pay for using particular routes atdifferent times of the day.This system,__________ (57)as“road pricin9”,is alreadybeing introduced in a__________ (58)of cities,using aspecial electronic card__________ (59)to the windscreen of the car.Another way of__________ (60)with the problem is to provide cheapparking on the__________ (61)of the city,and strictly control the number ofvehicles allowed into the centre.Drivers and their passengersthen use a special bus__________ (62)for the final stage of their journey,Ofcourse.the most important__________ (63)is to providegood public transport.However,toget people to__________ (64)the comfort of their cars,publictransport must be felt to be reliable,convenient andcomfortable,with fares__________ (65)at an acceptablelevel. A . blockedB . keptC . given