Teachers, save “Mystery Science: Why do builders need so…” to assign it to your class.

1. Tap and listen to Mystery Doug read the story. 2. Return to and tap . 3. Select . Draw a picture of your favorite big machine. 4. Select . Finish the sentence: My machine is called a _____. Then circle a word for the kind of work it does. 5. Select . Read your sentences out loud. 6. Tap to save and submit your work.