在探究“电流与电阻的关系”的实验过程中，小明选择了5Ω、10Ω、20Ω、25Ω五个电阻进行实验，电路图如图甲所示．

    In a small village, there is a teacher, a doctor, a driver, and a policeman. The four men are good friends. What are their names？One is Tom, one is Jack, one is Mike and one is John. Mike's, Jack's and Tom's children are classmates. John has no children. He teaches his friends’children at a middle school. Mike works at a police station. He loves his job very much. Jack has a car. He often drives his car to go to work or visit his friends. The doctor's house is next to the driver's, so the children often play together.