Sentence 1: Amy wore flip flops indoors all year long. 
 Sentence 3: As Amy was going down stairs her foot slipped through the flip flop 
 Sentence 4:  Amy tumbled down the stairs 
 Sentence 5:  Her sister laughed at her for breaking her cheap flip flop 
 Given Sentence 2: Her sister laughed at her for wearing flip flops instead of slippers.