1: "Simone Biles secures her 21st world title as a record-breaking US gymnast."

2: "The unstoppable Simone Biles continues to dominate the gymnastics world with her incredible talent."

3: "Simone Biles proves why she is a force to be reckoned with in the gymnastics arena."

4: "Breaking records left and right, Simone Biles solidifies her status as a legend in gymnastics."

5: "Simone Biles's 21st world title cements her legacy as one of the greatest gymnasts of all time."

6: "No one can match Simone Biles's level of skill and dedication to her craft in gymnastics."

7: "With her 21st world title, Simone Biles continues to raise the bar for excellence in gymnastics."

8: "Simone Biles's relentless drive and passion for gymnastics shine through in her 21st world title win."

9: "Simone Biles's 21st world title is a testament to her unparalleled talent and determination in gymnastics."