Sentence 1: A boy's CD was skipping. 
 Sentence 3: He decided to clean it with the same stuff he used on CPUs 
 Sentence 4:  So he grabbed a bottle of pure acetone 
 Sentence 5:  It melted a hole clean through the CD 
 Option 1: It wasn't scratched, so he figured that it must be too dirty. 
 Option 2: It was scratched beyond repair.