Sentence 1: Lanie's teacher had everyone in the class get a pen pal. 
 Sentence 3: Their friendship grew from their childhood into their teen years 
 Sentence 4:  They stopped writing and began using the phone to keep in touch 
 Sentence 5:  When Lanie and her friend were adults, they finally met in person 
 Option 1: Lanie stayed in touch with her pen pal long after the school year. 
 Option 2: Lanie stopped talking to her pen pal after the school year.