Complex sentence: Protest rioting became so intense during some years in the 1970s that tanks occasionally patrolled the streets of major Moroccan cities; casualties among demonstrators occurred in Casablanca in 1981 and in Fes in 1990.
Split into simpler sentences: Protest rioting became so intense during some years in the 1970s that tanks occasionally patrolled the streets of major Moroccan cities. Casualties among demonstrators occurred in Casablanca in 1981 and in Fes in 1990.