Complex sentence: After returning from China, the Powells bought an old house on Potrero Hill in San Francisco, California, fixed it up, and sold it for a profit, and did the same thing, buying, rehabilitating, and reselling fourteen houses and several apartment buildings.
Split into simpler sentences: After returning from China, the Powells bought an old house on Potrero Hill in San Francisco, California, fixed it up, and sold it for a profit. They settled into a pattern of buying, rehabilitating, and reselling fourteen houses and several apartment buildings.