听力原文： One of the main complaints of city residents, not surprisingly, is the lack of parking. This problem is partly caused by all the abandoned cars on the streets. It has been estimated by A to Z Towing, Inc., a nationwide tow-truck agency, that over one million cars are abandoned on the streets and alleyways of the nation's cities. Each year, approximately a third of those cars are removed and destroyed. The rest of the cares which are not removed take up parking spaces and make neighborhoods look rundown. In Boston the problem has been dealt with by a non-profit governmental agency called Street Horizons, which uses the money from the recycling of the metal in the cares to pay for the most cost of towing them. The program in Boston sounds good although it has not completely reached financial independence from the federal government yet. Until a truly self- sufficient program for removing old cars is developed, it will remain a serious problem. How many cars are towed from the streets each year?