Complex sentence: He was promoted to the State Planning Committee chairmanship, became Khrushchev's First Deputy Premier in 1960, and regained his old seat in the Politburo at the 22nd Party Congress in 1961.
Split into simpler sentences: He was promoted to the State Planning Committee chairmanship, and became Khrushchev's First Deputy Premier in 1960. Kosygin regained his old seat in the Politburo at the 22nd Party Congress in 1961.