Sentence 1: Jackson wanted to run a half-marathon. 
 Sentence 3: He soon was able to run faster than his friends 
 Sentence 4:  He participated in the half-marathon with his friends 
 Sentence 5:  He beat all of them to the finish line 
 Option 1: He started to train everyday. 
 Option 2: He twisted an ankle while training and had to drop out.