Sentence 1: Lily was at the dentist's office. 
 Sentence 3: The dentist examined her teeth and pronounced her cavity-free 
 Sentence 4:  She took a free toothbrush and made her next appointment 
 Sentence 5:  Lily left with a clean smile and a sense of relief 
 Given Sentence 2: The hygienist cheerfully scraped plaque and recommended more flossing.