Two French brothers invented the hot air balloon. They made the balloon out of paper and filled it with smoke. The smoke warmed the air inside the balloon. This made it lighter than the cool air outside the balloon. It was light enough to rise into the sky.
Which sentence best summarizes the passage?
Answer: "Two French brothers built the first hot air balloon, warming the air inside with smoke so it would rise."
This sentence covers who did the action, what the action was, and the end result. The other sentences on give a partial idea of the sequence and full events.
