[susan53]

It depends. The continuous form expresses temporary events - ie events already started but with a predictable end, while the simple form expresses permanent events - events that were true yeaterday, are true today and have no planned end. So :

Two of Ann's friends are married to Frenchmen. They live in Paris. - ie they're they're permanently as far as current plans are concerned.
But :

A couple of Ann's friends have decided to spend their gap year improving their French. They're living in Paris for 10 months - ie they're there temporarily and the action has a clearly intended end point.

Very often the distinction is more subjective than objective. For example, after I'd been in Italy about 10 years, I started to say I live in Italy. But my mother went on much longer saying My daughter is living in Italy - because of course she wanted to believe that it was only temporary and that I'd go back.