Sentence 1: Ben and his friends were sitting on top of a hill. 
 Sentence 3: When he reached the bottom his friends said they wanted to try too 
 Sentence 4:  His friend began to copy Ben but slipped off halfway down the hill 
 Sentence 5:  He hurt his arm badly and Ben and his friends called an ambulance 
 Option 1: Ben got up and walked down the hill. 
 Option 2: Ben sat down on his skateboard and sped down the hill.