Sentence 1: Bob sat around all day. 
 Sentence 3: But he saw a lost dog outside of his house 
 Sentence 4:  And he decided to take care of him 
 Sentence 5:  Bob was happy to make a difference in dog's life 
 Option 1: And he thought he was useless at the office. 
 Option 2: And he thought he was useless.