Complex sentence: After producing programs for broadcast on other stations for about 20 years, the University of Michigan applied for an AM frequency in the early 1940's, but the FCC turned down the application because there weren't any openings available.
Split into simpler sentences: After producing programs for broadcast on other stations for about 20 years, the University of Michigan applied for an AM frequency in the early 1940's. But the FCC turned down the application because there weren't any openings available.