Here are the completed dialogues:
A: What school do you go to?
B: Hillside Secondary. What about you?
A: Clifton Primary School. Oh! How old are you?
B: 1) I'm eleven. My sister goes to Hillside Secondary.
A: 2) She is in Class 4D.
B: Is Dan a student?
A: Yes, 3) he is.
B: 4) Is he at Broadoak School?
A: Yes, 5) he is.
C: How old are Tom and Carrie?
B: Tom is 12 and Carrie is 13. 6) They are students.
A: Oh! Which school?
B: Green School. 7) It's a very good school.