At East China University of Science and Technology, students who finish their food in the dining hall can get a coupon  when they return their tray . They can exchange coupons for small gifts, such as books, magazines, mobile phone covers and hand warmers. "It's been a big surprise," said Liang Zhaoyun, 19, a student in the university of Shanghai. "It makes us try our best to finish the food!" But some food in the dining hall is so poorly prepared that students are _ to finish it all. Some schools have paid some attention to it. "The dishes in our canteen are all right, generally speaking. We've tried our best to make it tasty. But of course it's difficult to make all the students love it." said Wang. Other universities also pay attention to the size of food. At Nanjing University, rice is divided into three different-sized bowls that students can choose from. "I like to try different dishes at each meal. So I had to throw away a lot of food because the bowls were too big. But now the dining hall offers small sizes. It's great because I can try different dishes at half price and don't waste so much food," said Fan Peng, a student from Nanjing University. But what if you really can't finish all your food? Some universities also provide a take-away service. If you can't finish all your food, you can get a box to take the leftovers home. Even if you feed the cat, it's not wasted. So you see, if we call on students not to waste food, schools should also improve the service and meal quality. How can the students at East China University of Science and Technology get a coupon?
They eat up all the food and wash the tray. They return the tray in the dining hall. They finish all the food and return the tray. They wash the tray and return it.