Annie sometimes felt puzzled by the relationship between her parents. They never seemed to show much love for each other. Annie believed that people who were in love would show it. They would hold hands, speak sweet words to each other and give each other nice gifts. Annie's parents did none of these things. So, she doubted whether they really loved each other. It was Annie's plan to ask her parents about their feelings for each other. But it was hard to find the right moment. One Saturday afternoon, she noticed that her dad was in the garage, doing some work on the engine of his sports car. Annie's dad was always in a good mood when he was near his sports car, so she decided to ask him the question that had been bothering her." Dad, do you and Mom really love each other?" "Of course," her father replied. "Why do you ask?" "Well, you never seem to show it." Annie's father was silent for a while, he spoke again. "Look at the engine of this car," he said. "It is oily and messy, and the car looks much better when the hood   is down. Don't you agree?" Without waiting for a reply, he went on. "If I took out the engine and put the hood back down, the car would look just as beautiful, right? But it wouldn't be a car anymore. The engine is its beating heart. You don't usually see it, but it has to be there. It's the same with your Mom and me. Our love for each other is the beating heart of this family. Don't worry just because it isn't on show all the time. " About six months later, Annie's father lost his job. The family had to cut back on many things to make ends meet.  And he had to sell his beloved sports car. But Annie noticed another change. Because he had more free time, her father spent more of it with her mother. They seemed to grow closer together, and showed their love more often. Their love, which Annie had been afraid did not exist, was plain to see. Annie was sad that the sports car had gone, but at least she understood what her father had told her that day. What is the main idea of the article?
Children should pay attention to parents' love. It's not good to show the feelings on the outside. Love may not be seen, but it doesn't mean it isn't there. We don't truly appreciate what we have until it is gone.