Complex sentence: While her husband was serving in the Second World War she continued working in the factory, and a co-worker introduced her to the American Negro Theatre, where she studied acting; other graduates included Harry Belafonte and Sidney Poitier.
Split into simpler sentences: While her husband was serving in the Second World War she continued working in the factory. A co-worker introduced her to the American Negro Theatre, where she studied acting; other graduates included Harry Belafonte and Sidney Poitier.