Answer:
we use "on" when we are referring thing that is on top of something such as "the book is on the table", but "at" is a location noun that you use it like "I am at the store". "in" is when we use it when we are inside of something such as "I am in the building." or "she is in there"
Explanation:
usually is "on" is used when something/someone is on top of something
"at" is the location noun
"in" is when you are inside of something
