Complex sentence: During World War II as the western part of the Soviet Union (including Russia) was invaded by Nazi Germany, about 600 km. of electrification was dismantled Исаев p.25 but after the Germans were driven out, some dismantled electrification was reinstalled.
Split into simpler sentences: During World War II as the western part of the Soviet Union (including Russia) was invaded by Nazi Germany. About 600 km. of electrification was dismantled Исаев p.25 but after the Germans were driven out, some dismantled electrification was reinstalled.