1) Fireman is a person who helps people in dangerous situations, which contains fire. He also helps with taking cats from trees. Without fireman everything will just burn.
2)Doctor works i hospitals. He makes diagnosis and treats people. Without doctor lot of people could die.
3) Lawyer is a person, who is connected with law. He works in governments. He tries to help people, in order to they don't have to go to jail.
4)Cook is a person who cooks. He usually works in restaurant. He makes lot of delicious dishes.
5)Teacher is a person who teaches in schools. He helps children and adults to learn something. He usually has a big knowledge.