A、By reading nutrition facts instruction. B、By tasting the food himself. C、By consulting the authority. D、By making scientific r

It’s unrealistic to think that the average person, who’s faced with fast food and processed food on a regular basis, can start following a completely rigid diet of 100 percent "clean" fresh or local foods. While it may work for some people, it’s not reasonable for the masses as issues of seasonality and transportation make it difficult for all of us to access fresh and local foods all the time. The 2010 Food Factor Survey revealed just how dependent today’s cooks are on convenience foods. Of 3 000 women surveyed from across the United States, 70 percent of them purchased convenient produce which are prepared salads and chopped fruits and vegetables, and 80 percent purchased convenient forms of fresh meats regularly. According to the US Department of Health and Human Services, the quest for convenience is leading more people to consume quickly accessible meals to prepare at home. When the wrong choices are made, the trend contributes to obesity, especially among children. However, most people,might think many processed foods can deliver lots of nutrition without doing you any harm. The best way to assess the food’s value is to understand its nutrition facts tag. Besides the basics of paying attention to calories and serving size, some tips from the Food and Drug Administration may guide you, such as choosing products with high daily value percentages of fiber and of vitamins and minerals, looking for low daily value percentages of total fat, and noticing some sugar-added terms like corn syrup and fruit juice concentrate, which contain lots of calories but little nutritional value.
16. What can we learn from the passage?
17. How many the surveyed women in the US purchase convenient fruits and vegetables?
18. What problem will the convenient produce cause?
19. How can a person know the food’s value?