Complex sentence: Molotsi was responsible for the pieces in Sesotho in the bulletin called The Africanist which he become the editor in 1955 and was succeeded three years later by Robert Mangaliso Sobukwe.
Split into simpler sentences: Molotsi was responsible for the pieces in Sesotho in the bulletin called The Africanist which he become the editor in 1955. Molotsi became the editor of the bulletin in 1955 and was succeeded three years later by Robert Mangaliso Sobukwe.