معنى at

I work at a company that specializes in artificial intelligence.

My father came from work at five o'clock.

I met my friend at the sweet shop.

I'll meet you at the restaurant next door to my grandmother's house.

Customers entered and took their places at the table.

My friend smiled at me.

I will be able to get a driver's license at the age of eighteen.

At what time do you want to meet me?