It is Sunday today. Anna goes shopping with her mother. She wants her mother to buy a new coat for her. In Hongxing Shop, she finds a green coat. She tries it on. It's too small. She wants a big one, but the big one is not green. Anna doesn't like other colors.” Let's go to another(另外的)  shop to have a look.”her mother says. Then they go to Jiajiale Shop. The shop is big and they see many kinds of coats in different colors and sizes(尺码). Anna tries on a green one. It looks nice on her. So they take it for forty-five yuan.

我国四大地理区域中农作物一年一熟或两年三熟的地区是____地区；我国机械化程度最高、提供商品粮最多的粮食基地是____平原。

小肠的哪一结构特点与吸收营养物质的功能无关（　　）