Найдите в диалоге Present Perfect Continuous выпишите
Dave: Hi Tim. What's up?
Tim: Oh, hi Dave! What are you doing here?
Dave: Oh, I've joined the Eco-helpers club.
Tim: Oh yeah, I've heard about that. Sally collects rubbish for recycling in the park every Saturday morning, doesn't she?
Dave: That's right. She's been doing that for a month. I've been building nesting boxes.
Tim: Nesting boxes?
Dave: Well, there aren't many trees left in the city for birds to build their nests. If we don't help them, they will have to leave the city.
Tim: That's interesting. What else have you been doing?
Dave: We've been planting trees and cleaning out ponds for a week now that the weather's good.
Tim: Your club sounds wonderful. I could join as well, couldn't I?
Dave: Of course you could. We really need volunteers, but you have to see Miss Jackson first. She'll tell you what to do.
Tim: Sounds great! I'll join first thing Monday morning.