题目

阅读短文，选择正确的答案 .Last Sunday, Peter went swimming in a lake. The weather was fine. There were many people by the lake. A little boy was playing by the lake, too. Suddenly, the boy fell into the lake. He was too little to swim. Then a strong man jumped into the lake and swam to that boy. He brought the boy back to the bank (岸边). The boy's parents were very grateful(感激的 ) to the strong man.【1】When did Peter go swimming in a lake? ( )A.Today. B.Last Sunday. C.Last Saturday.【2】What was the boy doing at first? ( )A.Crying. B.Playing. C.Singing.【3】Who jumpe（本小题满分12分） 已知集合,,若，求实数的取值范围．