an airport ,a bank ,a chemist's 中chemist's 是指在哪里呢?

an airport ,a bank ,a chemist's 中chemist's 是指在哪里呢?
Simon has been to schooll lots of times. He likes it very much. He has lots of food, because the children bring sandwiches for their lunch and drop some crumbs.
Simon knows the children come to school only on weekdays. Do he often comes to school on Fridays and gets enough food for the week.One Monday, no one came. Simon waited. But still no one came. Simon felt very sad. Then on Tuesday Simon got a letter.It said,"Dear Simon. Don't be sad. We are on a holiday now, but we'll be back!" Simon eas very happy because the children would be back and he would have food again!
Questions:1. Who is Simon?
2. How often has Simon been to school?
3. Why couldn't Simon find any children on Monday?
4. What did Simon get on Tuesday?
(还有weekdays 是指哪几天呀?）