1.   She watched as the bubbles rose to the surface and popped.

2.   She watched the bubbles rise to the surface.

3.   When water boils, bubbles rise to the surface.

4.   Bubbles rose to the surface of water.

5.   Tiny bubbles rise up through the darkness and a soothing voice calls the audience into the sight room.

6.   Big bubbles will rise from the bottom of the pot.

7.   After a little while, the bubbles rise to the top and are gone.

8.   My musings were interrupted by a gradual awareness that the bubbles were rising.