Martha / Jacob
Not Bell as in Alexander Graham. You must be talking about a different Bell. What year was it?
There isn't. Not enough to breathe. I've been on a lot of planets that do have breathable air, though. Outside our galaxy. Sometimes far, far outside our galaxy, but I've been back on Earth for a while now. Still getting into trouble, though.
Not entirely destroyed, and they did rebuild it. Earth has been in the middle of a lot more intergalactic politics and attempted invasions than we really quite knew what to do with, but we had the Doctor, and I traveled with him for a while. Now we have UNIT, to deal with the situations that come up when he's not around. I worked for them, before I got here.