Ken: Today is Teachers’ Day. Let’s go to our school. That’s our school.

Jane: Hello, Mocky. Welcome to our school.

Mocky: Thank you

Jane: These are our teachers. This is our math teacher, Miss Wang..

Ken: Here’s our classroom. That’s our English teacher, Miss Li.

Jane: Happy Teachers’ Day, Miss Li. This is our friend, Mocky.

Miss Li: Hello, Mocky!

Ken: Don’t touch, Mocky! Let’s go to the playground!

Mocky: Great!

Mocky: Whose ball is this?

Ken: That’s their ball. This is our ball.

Ken: Be careful, Mocky!

Mocky: Oh, I’m sorry,

Ken: That’s the teachers’ office.

Q: Whose ball is this?