Complex sentence: The Douglas company began delivering the production model A- 26B in August 1943 with the new bomber first seeing action with the Fifth Air Force in the Southwest Pacific theater on 23 June 1944, when they bombed Japanese-held islands near Manokwari.
Split into simpler sentences: The Douglas company began delivering the production model A- 26B in August 1943. Invaders first saw action with the Fifth Air Force in the Southwest Pacific theater on 23 June 1944, when they bombed Japanese-held islands near Manokwari.