What homework did you do in the holidays？ Now homework is not simply about exercises．It can be survey，practice and even work experiences．Here's three students' homework．

Sam bought 10kinds of snacks．Then he checked their instructions and wrote down the amount（数量）of sugar and fat in the snacks．He was doing his biology（生物学）homework．"We are told it is not good to eat too many snacks．They have high calories（卡路里）．But we don't care about it，"he said．Sam spent three days studying the instructions．

He realized it was true．With some plasticine（橡皮泥），glass balls，a ping﹣pong ball and a piece of paper，could you make a tumbler（不倒翁）？This is the physics homework of Mary．"Next term，we will learn about the center of gravity（重心）．This homework made me more interested in physics，"she said．

Lisa worked as a guide in the local museum．She got a guide book from the museum，but she still did a survey and added more information to her introduction．She worked three hours a day and had no time to  take a break．But she felt it was a meaningful experience．"My communication skills improved，"she said．

The title ， （81）
Sam	Survey	It （82） 　　study the snack's insrutions． He realized it was bad to eat many snacks．
Mary	（83）	She made a tumbler with 4materials． She （84） 　　physics．
Lisa	Work experiences	She worked （85） 　　in the local museum for 3house a day withput a break． She improve her communication skills．