Read the dialogue below in turn with your classmate, then answer the questions!

Sari: You got the highest score on the Mathematics test, didn't you?

Nina: That's true, Sari. I got ten.

Sari: You're a genius!

Nina: Thank you. What about you?

Sari: I only got seven. The test was so difficult.

Nina: Indeed. I was lucky to answer all the questions.

Sari: No, you are excellent. That's why you always get good scores.

Nina: Your scores are not bad.

Sari: They are not as perfect as yours. I hope to get ten on the next Mathematics tests.

Nina: Sure, you can. You just need more practice.

Who are they in the dialogue?