如图，是一个三级台阶，它的每一级的长、宽、高分别为20dm、3dm、2dm，A和B是这个台阶两个相对的端点，A点有一只蚂蚁，想到B点去吃可口的食物，则蚂蚁沿着台阶面爬到B点的最短路程是（   ）

小肠的哪一结构特点与吸收营养物质的功能无关（　　）

①—You are Danny.

—Yes. I'm Danny.

②Look，I'm tall and fat. Who am I?

③Look at my eyes. My eyes are small and brown.

④My nose is big. My mouth is big，too.

      There are  1 days  2 a week. They are  3 , Tuesday, Wednesday, Thursday, Friday, Saturday and4  .Sunday is the first day 5 a week. Monday is the second day of a week. The last day of a week is Saturday.  6  China, people work 7days a week. They go to work from Monday 8  Friday. They don't go to work 9 Saturdays and Sundays . They stay 10  home.