2. Complete the sentences with the Present Perfect Continuous form of the verb in brackets. 1. The Eco-helpers _________ (plant) trees in the park since early morning. 2. I _________ (look) for my mobile phone for half an hour, but I can't find it. 3. She _________ (not / collect) rubbish this week because she has a broken arm. 4. How long _________ they _________ (work) on the environmental project? 5. The river looks much cleaner. Local people _________ (clean) it for two weeks. 6. _________ you _________ (wait) for the bus since 8 o'clock?