Complex sentence: The Spartakiads were used by the regime as a tool of massive propaganda and were thus attended by large numbers of people, for example, at the 1960 Spartakiad about 750,000 gymnasts from the whole country took part and over 2,000,000 spectators witnessed the event.
Split into simpler sentences: The Spartakiads were used by the regime as a tool of massive propaganda and were thus attended by large numbers of people. At the 1960 Spartakiad, for example, about 750,000 gymnasts from the whole country took part and over 2,000,000 spectators witnessed the event.