Составьте примеры к at/on/in к каждому из них по три примера срочно!

At:  Meet me in the park at 7pm I want to study at the university in a couple of years I was at the dentist's yesterday.  On:  Scientists say there's water on Mars I do aerobics on a regular basis  My mom always includes bread on the shopping list In:  I have been living in Russia since I was born  I don't like when things are not in their places, especially when I'm looking for something There are 25 (замените число на ваше) students in my class.