What are their jods?

I guess you mean jobs.

Teachers are persons who teach us in schools.
A barber is a person, who cut our hair
A postman is a person, who delivers letters or parcels to us.
A bus- driver is a person, who drives buses.
A musician is a person, who plays music.
An author is a person, who writes stories or books.
A librarian is a person, who works in a library.
A policeman is a man, who keeps the society in order and catches thieves.
A fireman is a man, who puts out fire.
A tailor is a person, who makes dresses or clothing for us.
A carpenter is a person, who makes furniture or anything from wood
A baker is a person, who makes cakes or breads.
A cook is a person, who does cooking.
A nurse is a person, who look after patients in hospitals
A doctor is a person, who take care of patients in hospitals or cliniics .
A cobbler is a person, who repairs shoes

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I take the liberty to make some corrections on Ling’s answer to 陳彥如彥如’s question. No offence.

A barber is a person who cuts men’s hair and sometimes to shave them. (It is usually a man’s job) You have hairdressers for women.

A postman is a man who collects letters and delivers letters or parcels to us.

A librarian is an information professional trained in library and information science. Librarian needs a degree in Librarian Science before you apply for the job as a librarian in North America. Other workers who work in the library are library helpers, library assistants, library technicians and library clerks. Any person who works in the library is not necessarily called a librarian. Most dictionaries define librarian as someone who works in the library.

A tailor is a person whose job is to make men’s clothes that are measured to fit each customer perfectly. You have dressmakers and fashion designers for women.

Cobbler is an old-fashioned word. Nowadays we use the word “Shoemaker” instead. Cobbler has a different meaning. It usually means cooked fruit covered with a sweet bread-like mixture.

A cook is someone who prepares and cooks food as their job.

Both doctor and nurse can take care of patients. The distinction between doctor and nurse is not clear. A nurse can work in a clinic as well.

A doctor is someone who is trained in medical science, whose job is to treat people who are ill or injured.
 
A nurse is someone whose job is to look after people who are ill or injured, usually in a hospital.