1. A -----

   B Oh, I have already seen it twice

2. A Do you know that Mrs Jones has been working here for sixteen years?

   B I thought she started working here 10 years ago.

3. A Have you ever met anyone famous?

   B Yes, last summer I sat next to Brad Pitt on a plane to LA.

4. A How long ago have you started painting?

   B Ten years ago. I recently completed a painting that the National Gallery asked me to do a year ago.

Tada!!! :)