Mario's teacher asked them to research different snacks. He bought 10 kinds of them and checked the amount of sugar, fat and so on, in each. "We are told many snacks have high calories (卡路里)，but pay no attention to it," he said. But now he realized it was true. He said the homework was interesting and helpful.

With some plasticine (橡皮泥) and a ping-pong ball, could you make a tumbler (不倒翁)? This is Nancy's homework. She cut the ping-pong ball in half and made it the bottom of the tumbler with plasticine. "This homework made me more interested in physics," she said.

Sandy worked as a guide in the museum. In order to do the work better, she did research and added more information to her introduction. It was hard work, but she felt it was a fun and meaningful experience. "I learned how to do research, and my communication skills are also improved," she said.