Sentence 1: The alarm bell rang in the firehouse. 
 Sentence 3: The firefighters ran to the fire trucks 
 Sentence 4:  The big doors of the firehouse swung open 
 Sentence 5:  The fire trucks raced towards the fire 
 Option 1: A fire had begun at a chemical plant. 
 Option 2: The firefighters quickly put on their coats, boots, and hats.