Sentence 1: Heidi worked at a clothing store in the mall. 
 Sentence 3: One day, Heidi had to help a young woman with a purchase 
 Sentence 4:  The woman was very nice despite how Heidi was treating her 
 Sentence 5:  Heidi was surprised, and realized that she needed to be nicer at work 
 Given Sentence 2: She was usually very sour at work, especially when helping customers.