单项选择题
A．Traffic Crowding in New York City B．Air Pollution in New York City by Cars C．Special Lanes for Passengers D．A Solution to Traffic Problems in New York
A．narrow passages between buildings for bicycles B．roads full of bicycles C．special parts of the road for bicycle riders only D．roads for bicycles only
A．are more convenient than cars B．are safer traffic tools than cars C．are ridden by most people inUS D．are the solution to some city problems