Complex sentence: The 357th FG served initially as an escort group, providing penetration, target, and withdrawal support for bombers that attacked strategic objectives on the Continentand began operations in the assault against the German Air Force and aircraft industry during Big Week, 20-25 Feb 1944.
Split into simpler sentences: The 357th FG served primarily as an escort organization, providing penetration, target, and withdrawal support for bombers that attacked strategic objectives on the Continent. Participated in the assault against the German Air Force and aircraft industry during Big Week, 20-25 Feb 1944.