6. Complete the sentences with a, an or – (no article). She's_____a______ doctor. He's ____________artist. They're ____________ engineers. I'm ____________ teacher. We're ___________doctors. You're ___________ musician. She isn't ___________artist. I'm not __________ student. You aren't ___________teacher. He isn't ____________engineer. They aren't ____________ nurses. You aren't ___________ artist.