根据下列短文内容，选择最佳答案。

　　You prlbably know the food pyramid(金字塔)well enough．It is a food pyramid with horiaontal stripes(水平线)．Carbohydrates(碳水化合物),such as bread, rice and potatoes, are on the dase of the pyr-amid．They are most of our everyday food．The fats and oils(脂油)are at the top of the pyramid．We should eas the least of them．

　　Well, the food pyramid．with vertical stripes(垂直线)．Instesd of the horizontal stripes, the vertical stripes mean the five food groups and fats and pyrmid．This is because not all foods in a food group give us the same health benefits(好处)．A fresh apple, for example, would be on the base of the pyramid, while an apple pie would be at the top Tis shows that we can eat more fresh(阶梯)going up the side This shows us how important exercise is．It also shows us that we will be healthier and healthier if we take exercise every day．

　　Sp wju did some American experts change the pyramid? They did this to do a better job of tell-ing people how to be healthy．The new pyramid tells us to have dalanced(平衡的)food from each food group eery daly．and it shouw us that we need Iess of some us kinds of food than othen, For ex－ample, you need less meat or fish than rice or fruit．It also shows us that not all foods in a groupgive us the same health benfits, and that exercise is quite important in oru everyday life．