1. What have you (been doing) these three months?
2. Our train starts late in the evening, so if you (come) at seven o’clock, we shall still (be packing) our luggage.
3. When did you (see) him last?
4. I (met) him when he (was walking) across the park.
5. Have you ever (acted) on the stage? – Why, yes, that’s what I (have been doing) for the last six years.