题目

Choose what to eat is no longer as easy as it once was. Our eating habits  1.         have changed , as have our way of life. And the fuel we need for our       2.         body is also different. Tradition diets often have too much fat and too      3.          much calories for the 21st-century person. If we want to keep up with the   4.         high pace of modern life, we had better to learn to make the right choices   5.        about what and how we eat. Because we have so much to choose, many    6.        companies offer advic一种水笔，原价每盒18.6元，现价每盒l5.81元，求：现价比原价降低了百分之几？