C. 1. been standing, been queuing

    2. had, broken

   3. left, been sitting, noticed

B.1.Paul, why are your hands so soft?

Because I have been doing the washing-up.

2.Are the onions ready for the pan?

Yes, Carol has been peeling them/Yes, Carol has peeled them.

3.  Rachel, you look tired.

Yes, I have been cutting the grass.

4.  Tim, your hands are very cold.

Yes, I have been defrosting the fridge.

5.Are the floors clean?

Yes, Niel has swept them.

6.Why are your eyes red, Carol?

Because I have been peeling onions.