Sentence 1: Jeff spent all night studying. 
 Sentence 3: He had crammed all night and it was now 7 AM 
 Sentence 4:  He started to get ready for class, and sat on the couch for a second 
 Sentence 5:  Next thing he knows, he wakes up and it's 3PM! 
 Given Sentence 2: He had a big calculus exam at 8 AM.