根据短文内容选择。I am Mike. I have a neighbour. He is a young man. He is not tall but strong. He always goes out at night and comes back home in the morning.
One day, I met him at the gate. He wore a pair of sunglasses, a black mask(口罩) and a black T-shirt. He looked unhappy. His wife asked him, "Did you use knives yesterday?""Yes," he answered. I thought he was going to rob(抢劫) a bank! Then he turned around and smiled at me, but I was afraid of him.
The next day, I met him again. But this time, his son asked him, "Did you help people yesterday?""Yes. A lot" he answered. Suddenly,I knew his job! He is a doctor. He always goes to the hospital and helps others at night. He usually wears a pair of sunglasses and a black mask because he is tired. He doesn't want to show his tired face to his neighbours!