听力原文：M: Welcome to my house! W: Well, Mr. Robinson, I' m greatly surprised with all the work you've done on your house. (19)How long have you been working on it? M: (19)I first became engaged in Do-it-yourself work several years ago. You see, my son Paul is disabled since childhood. (21)He's always in the wheelchair and(20)I just had to make some changes for him to the house. W: Then, what sort of changes did you make? M: First of all, some practical things to help Paul. Just imagine the problems a disabled person would have in your house. We need a large house with wide corridors so that Paul could move from one room to another as he like. W: What else did you do? M: By the time I'd altered everything for Paul, Do-it—yourself work had become a hobby of mine. I really enjoyed doing things with my own hands. W: What are you working on now? M: I've just finished the kitchen. (21)Now I'm building an extension so that Paul will have a large room on the ground floor where he can work. W: I heard that you have got a prize of $10 000 in the Do-it-yourself Competition. How are you going to spend it? M: (22)I'm hoping to start my oven business soon so that I can convert ordinary houses for disabled people. I think I've become an expert on the subject. (23)