Sentence 1: Martha carried her basket of laundry down the hall past her neighbor. 
 Sentence 3: A big pile of her underwear fell right on her neighbor's feet 
 Sentence 4:  Clutching his stomach, her neighbor howled with laughter 
 Sentence 5:  Snatching up the underwear, she flushed scarlet with embarrassment 
 Given Sentence 2: Since I wasn't looking at my feet, I stepped on a rock.