This book is intended for adults to read to their children, grandchildren, and loved ones. The words that are underlined once are called sight words. Stress and repeat these words to reinforce learning them. Dr. Straw has two lines under words called combining words. This means I can read! (Word with single underline + word with double underline = yes, I can read!) Take the challenge questions: 1. What kind of car did Frank drive? 2. Did Frank chase the mouse up the stairs or down? 3. What else was crooked on the house? The following are the answers: 1. It looked like a tank that could be started with a crank. 2. Both. 3. The front door.