My best friend Bill is always trying to find out ways to give the environment a helping hand. One day, Bill brought some green cakes to school. At lunch, he shared his cakes with us. "Delicious!""Wonderful!" Everyone liked the cakes and wondered how he made them.
The story goes back a few weeks. Bill's family likes fruit very much. His father especially loves watermelons. He eats a lot of them in summer. They always throw away the skins(皮).
After seeing the cleaner working hard to pick up the heavy rubbish pail (插), Bill said. "There must be a good way to use all the watermelon skins. "
After a lot of thinking, he decided to make something with the skins. First, he made the skins into juice. Then he carefully made his delicious GREEN cakes.
Once he tasted the cake, he knew his cakes were a great by-product(副产品) of the watermelon eating. And it was nature friendly too.
From now on, he doesn't need to worry about the heavy waste from eating watermelons. And everyone always wants more of his special cakes.