Sentence 1: Ever since Smith was a small child, he had wanted a pet cat. 
 Sentence 3: Smith worked hard in school and was able to buy a big home 
 Sentence 4:  Smith purchased as many cats as he possibly could 
 Sentence 5:  Smith lived happily ever after with his cats 
 Given Sentence 2: The only issue is his mother is allergic to cat hair.