推理题 Four friends live in a small town. Their names are John, Miller, Smith and Carter. They all have different jobs. One is a policeman, one is a cook, one is a farmer, and one is a doctor. It's Tuesday afternoon. John’s son breaks his leg and John takes him to the doctor. The doctor's sister is Smith's wife. The farmer isn’t married. He has a lot of hens. Miller often buys eggs from the farmer. The policeman sees Smith and Miller every day for they are neighbors. 1. John is a _______. 2. Miller is a _______. 3. Smith is a _______. 4. Carter is a _______. A. doctor B. farmer C. policeman D. cook