听力原文：W: So you know what the White Lane Law is? M: In the United States, each state has a law that says blind people using canes or dogs have the same rights of public access as the sighted. W: What does it mean, then? M: It means that blind people can take their canes and dogs into public buildings, offices, restaurants, theaters, amusement parks, on houses, trains, planes and other public places. These laws were established from the work of the US National Federation of the Blind to make sure that blind people have the same rights as everyone else. W: Why do some blind people use dogs and others use canes? M: it is simply a matter of personal choice. Some blind people like using canes better, and some enjoy using dogs. W: Should I help a blind person across the street? M: If a blind person asks for help, then you may certainly help. You can ask if any help is needed, but understand that the answer may be 'no', Blind people, if they have learned to use a cane or dog and travel independently, may not need help. It is important not to grab someone who is blind. If a blind person wants help, he or she may take your arm, or simply walk beside you. Some blind persons may have a harder time hearing the cars and traffic, especially if there is construction or a lot of noise around the area. Then they might want help that they might not need at other times. W: Should I help a blind person to a chair? M: The same rules apply here. Some blind people will appreciate help in locating a chair, but some can find chairs, tables, and desks on their own. Sometimes a blind person may ask where the chairs or tables are, then go to them on his or her own. (20)