Sentence 1: Three summers back, I decided I wanted to adopt a dog. 
 Sentence 3: A local rescue agency had an adoption event at the park 
 Sentence 4:  While I was at the event, I found the cutest little black puppy 
 Sentence 5:  I adopted him right away, and he has been my best pal ever since 
 Given Sentence 2: Specifically, I wanted to adopt a little black dog.