Sentence 1: Arden needed his grass mowed, but he hurt his knee a few weeks ago. 
 Sentence 3: Finally he decided to call up a teenage boy he knew 
 Sentence 4:  Arden offered the teenager some money to mow his grass for him 
 Sentence 5:  That day the teenager came, mowed his grass for some pocket money 
 Given Sentence 2: The grass was getting very long because no one had mowed it.