One evening I went to have dinner with my uncle and aunt. They had 1invited another person, a young woman, so that there would be four people at 2. Her face was familiar (面熟的). I was quite 3　that we had met 4, but I could not 5　where I had seen her face. In the course of the talk, however, the young woman6to tell us that she had lost her purse the other day. All at once I remembered where I had seen her face. She was just the young girl in the photo in the purse I had picked up while walking down the street that afternoon, although she looked much older. She was7, of course, when I was 8　to describe her purse to her. Then I explained (解释) that I had recognized (认出) her from the photo I had found in the purse. My uncle insisted on going to the police station immediately to fetch the purse.
   As the policeman handed it 9 he said I had found not10the purse, but the person who had lost it.

已知函数y=x-5，令x=$\frac{1}{2}$ ，1，$\frac{3}{2}$ ，2，$\frac{5}{2}$ ，3，$\frac{7}{2}$ ，4，$\frac{9}{2}$ ，5，可得函数图象上的十个点．在这十个点中随机取两个点P（x₁，y₁），Q（x₂，y₂），则P，Q两点在同一反比例函数图象上的概率是（　　)

【环境保护】

    读西安市冬、夏季气体污染和能见度变化曲线，完成下列要求。