Bobby woke up because he heard a dog. He heard a dog barking outside his window. Bobby woke up when he heard the dog barking. Bobby got out of bed. He got out of bed and walked to the window. He looked out of the window. He saw a big brown dog. It was barking very loud. Bobby opened his window. He looked at the barking dog. “Why are you barking so loud？” he asked the dog. The dog looked at Bobby. Then it stopped barking.
　　1. Question： Why did Bobby wake up？
　　2. Mixed-up Sentence Exercise