Professions in Russian

A Russian language video talking about professions for introductions. "Here we'll talk about many professions in Russian." How to ask in Russian: "What is your profession?"

How to say or answer in Russian...
He is a gardener.
He is an engineer.
She is an actress.
He is an actor.
"I am a teacher" for both a woman and man. Я учитель.
She's an accountant.
She's a secretary. 
He's a shop assistant.
He's a president.
He's a mechanic.
He's a fireman.
She's a dentist.
He's a doctor.
He's a driver.
She's a babysitter.
He's a scientist.