Listen and read.
Mi: Hi, Nick.
Nick: Hello Mi.
Mi: You've bought a lot of things.
Nick: Yes. We're going on a picnic tomorrow. What are you doing at the supermarket, Mi?
Mi: I'm buying some eggs. Hey, what's this?
Nick: It's a reusable shopping bag.
Mi: Do you always use it?
Nick: Yes. It's better than a plastic one. If we use this kind of bag, we will help the environment.
Mi: I see. I'll buy one for my mum. Where can I buy one?
Nick: At the check-out. By the way, you're also green. You're cycling.
Mi: You're right. If more people cycle, the air will be cleaner. Right?
Nick: Yes. Oh, it's 5 o'clock already. I have to go now. See you later.
Mi: See you, Nick. Bye.