Read the following dialogue and then answer the questions.

Ghani: Ren, do you know how to remove bubblegum from clothes?

Nadya: Yes, I do.

Ghani: Can you show me how to do it?

Nadya: First, prepare a plastic bag. Put your clothes in the bag. Then zip it.

Ghani: I'm sorry. Could you please say it again?

Nadya: Okay. First, prepare a plastic bag. Put your clothes in the bag. Then zip it. Are you with me so far?

Ghani: Yes, I'm with you.

Nadya: After that, put it in the freezer for an hour. Let it freeze. After it's frozen, you can peel the frozen bubblegum from the clothes easily.

Ghani: Thanks, Nad.

27. What expression does Nadya uses to check for Ghani's understanding?