Complex sentence: The squadron was reactivated in July 1947 as a very heavy unit at Andrews Field, Maryland, where seven bombardment groups and their components were activated by Strategic Air Command (SAC) that day.
Split into simpler sentences: The squadron was reactivated in July 1947 as a very heavy unit at Andrews Field, Maryland. It was a component of one of seven bombardment groups activated at Andrews by Strategic Air Command (SAC) that day.