Sentence 1: The river was full people rafting down on inner tubes. 
 Sentence 3: He drifted for miles down the river before he hit some rapids 
 Sentence 4:  He awoke in a panic and paddled ashore 
 Sentence 5:  The guy looked around and wondered how long he was asleep 
 Given Sentence 2: They took a trip to the nursery to buy the plants they needed.