第一部分 阅读理解(共两节，满分40分)
第一节(共15小题；每小题2分，满分30分)
阅读下列短文，从每题所给的四个选项(A、B、C和D)中，选出最佳选项。
A
Despite the fact that two－thirds of Americans say they are on a diet to improve their health, very few are actually decreasing in size.“Dieting is a skill, much like riding a bicycle, and requires practice and good instruction, ” says Dr Bartfield.“You're going to fall over and feel frustrated, but eventually you will succeed and it will get easier.” According to Dr Bartfield, here are the top four reasons why many dieters fail to lose weight.
