Complex sentence: The National Radio Institute-McGraw Hill Continuing Education Center was a private post-secondary for-profit school, specifically a correspondence school, based in Washington, D.C., founded in the early 20th century, which originally catered to students desiring to become radio operators and technicians.
Split into simpler sentences: The National Radio Institute-McGraw Hill Continuing Education Center was a private post-secondary for-profit school, specifically a correspondence school, based in Washington, D.C., founded in the early 20th century. It originally catered to students desiring to become radio operators and technicians.