Complex sentence: In July 2012, Douglas and her teammates were featured on the cover of "Sports Illustrated" "Olympic Preview" issue, the first time an entire Olympic gymnastics team had been featured on the cover of the magazine.
Split into simpler sentences: In July 2012, Douglas and her teammates were featured on the cover of "Sports Illustrated" "Olympic Preview" issue. This marked the first time an entire Olympic gymnastics team had been featured on the cover of the magazine.