Complex sentence: From 1969 to 1971 Nimmo was a writer for "Jackanory", a long-running BBC television series comprising 15-minute episodes in which a professional actor reads aloud to children, sometimes with a still illustration.
Split into simpler sentences: From 1969 to 1971 Nimmo was a writer for "Jackanory". That BBC television program comprised 15-minute episodes in which a professional actor reads aloud to children, sometimes with a still illustration.