Complete with the present perfect continuous form of the verb in brackets.
1. He… (work) here for over ten years.
2. Jill… (swim) in this lake since she was a child.
3. How long … (you/ take care) of this injured bird?
4. They … (study) very hard for their exams.
5. My parents … (donate) to WWF for a long time.
6. The government … (try) to reduce pollution for years.