根据所给句子选出相应的职业

teacher　　doctor　　farmer    driver    policeman

①I work in a hospital. I help people. I am a ____．

②I work on the farm. I get many good things in autumn. I am a ____．

③I drive a bus every day. I can travel. I am a ____．

④I work at school. I love my students. I am a ____．

⑤I am very busy. I catch the thieves(小偷)．I am a____．