It's business.
Business is business.
He's away on business.
I am here on business.
None of your business.
He traveled on business.
It's none of my business!
This is my business address.
He has taken over his father's business.
His business was only a partial success.
It's my business to investigate such things.
My father often goes to America on business.
I'm not yet used to writing business letters.
We will now report on this year's business results.
I canceled my appointment because of urgent business.
Are you seriously thinking about starting your own business?