51. What did the author suspect back in 2016?
- A. Calorie consumption had fallen drastically over the decades.
- B. Most people surveyed were reluctant to reveal what they ate.
- C. The national statistics did not reflect the actual calorie consumption.
- D. Most people did not include snacks when reporting their calorie intake.
答案：C
答案句：We originally had this suspicion back in 2016, puzzled by the fact that national statistics showed calorie consumption falling dramatically over past decades. We found reliable evidence that people were drastically under-reporting what they ate.
参考译文：我们最初在2016年就有这种怀疑，当时我们对国家统计数据显示过去几十年卡路里消耗量大幅下降这一事实感到困惑。我们发现了可靠的证据，表明人们严重少报了他们的饮食摄入。
定位线索：题干“suspect back in 2016”→答案句“We originally had this suspicion back in 2016”；文中“national statistics showed calorie consumption falling”与“people were drastically under-reporting”对应选项C“The national statistics did not reflect the actual calorie consumption”。
解析：题干问作者2016年的怀疑，答案句明确指出作者对统计数据下降感到困惑，并发现人们严重少报饮食，即统计数据不真实。选项C是对此的同义转述。选项A是统计数据本身，不是作者的怀疑；选项B“reluctant”（不情愿）无中生有，文中是“under-reporting”（少报）而非不愿；选项D只是少报的一种表现，不是怀疑的核心。
53. What do we learn about obese people from the passage?
- A. They usually keep their eating habits a secret.
- B. They overlook the potential causes of obesity.
- C. They cannot help eating more than they should.
- D. They have difficulty recalling what they have eaten.
答案：D
答案句：Under-reporting rates are much higher for obese people, because they simply consume more food, and thus have more to remember.
参考译文：肥胖人群的少报率要高得多，因为他们摄入的食物更多，因此需要记住的内容也更多。
定位线索：题干“obese people”→答案句“obese people”；文中“have more to remember”对应选项D“They have difficulty recalling what they have eaten”。
解析：题干问肥胖人群的情况，答案句指出他们因吃得多而需要记住更多，暗示更难记住。选项D“difficulty recalling”是对“have more to remember”的合理推断。选项A“keep eating habits a secret”无中生有，文中未提保密；选项B“overlook causes”答非所问；选项C“cannot help eating more”偷换概念，文中说“consume more food”是事实，但未说“cannot help”（忍不住）。
55. What does the author suggest policymakers do about obesity?
- A. Remind people to cut down on snacking.
- B. Make sure people eat non-fattening food.
- C. Ensure people don't miss their main meals.
- D. See that people don't stick to the same diet.
答案：B
答案句：For policy, we need to focus on options that make it easy for people to eat fewer calories. If people do not know how much they are eating, it can be really hard for them to stick to a diet. Also, we should be looking for new ways to ensure what people eat wouldn't have much impact on their waistlines.
参考译文：对于政策，我们需要关注那些能让人们轻松减少卡路里摄入的方案。如果人们不知道自己吃了多少，他们很难坚持节食。此外，我们应该寻找新的方法来确保人们所吃的食物不会对腰围产生太大影响。
定位线索：题干“policymakers do about obesity”→答案句“For policy, we need to focus on”；文中“ensure what people eat wouldn't have much impact on their waistlines”对应选项B“Make sure people eat non-fattening food”。
解析：题干问作者对政策制定者的建议，答案句提出要确保食物不影响腰围，即吃不易发胖的食物。选项B“non-fattening food”是对“wouldn't have much impact on waistlines”的同义转述。选项A“cut down on snacking”文中未提，且与“make it easy”矛盾；选项C“don't miss main meals”无中生有；选项D“don't stick to the same diet”曲解原文，原文说“hard to stick to a diet”是问题，而非建议。