Read and study the following dialogue. Then, answer the questions that follow.

Rauf: Hi. I'm your new neighbour, Rauf. I live next door.

Maya: Oh, hi. I'm Maya. So, you just moved in? Do you need anything?

Rauf: Not right now. But thanks anyway.

Maya: Well, let me know if you do. Hm, by the way, would you mind turning your stereo down? The walls are really thin, so the sound goes right through to my apartment.

Rauf: Oh, I'm sorry! I didn't realise that. I'll be sure to keep the volume down. Oh, by the way, is there a good restaurant in the neighbourhood?

Maya: Yeah. There's a great one a couple of blocks from here. Try the soup. It's delicious.

What does Rauf say to express an apology?