Complex sentence: The seven small towns and villages, which were no longer any denser than the surrounding areas, were eliminated: this left the City of Toronto and the five townships, which at this time were redesignated as boroughs.
Split into simpler sentences: The seven small towns and villages, which were no longer any denser than the surrounding areas, were eliminated. This left the City of Toronto and the five townships, which at this time were redesignated as boroughs.