Section B Directions: There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A, B, C and D. You should decide on the best choice. I believe very strongly that our overproduction of cheap grain in general, and corn in particular, has a lot to do with the fact that three-fifths of Americans are now overweight. The obesity crisis is complicated in some ways, but it's very simple in another way. Basically, Americans are on average eating 200 more calories a day than they were in the 1970s. If you do that and don't get correspondingly more exercise, you're going to get a lot fatter. Many demographers are predicting that this is the first generation of Americans whose life span may be shorter than their parents'. The reason for that is obesity, essentially, and diabetes specifically. Where do those calories come from? Except for seafood, all our calories come from the farm. Compared with the mid-to-late 1970s, American farms are producing 500 more calories of food a day per American. We're managing to pack away 200 of them, which is pretty heroic on our part. A lot of the rest is being dumped overseas, or wasted, or burned in our ears. Overproduction sooner or later leads to overconsumption, because we're very good at figuring out how to turn surpluses into inexpensive, portable new products. Our cheap, value-added, portable corn commodity is corn sweetener, specifically high-fructose(高糖)com syrup. But we also dispose of overproduction in corn-fed beef, pork, and chicken. And now we're even teaching salmon to eat corn, because there's so much of it to get rid of. There is a powerful industrial logic at work here, the logic of processing. We discovered that corn is this big, fat packet of starch(淀粉)that can be broken down into almost any basic organic molecules and reassembled as sweeteners and many other food additives. Of the 37 ingredients in chicken nuggets, something like 30 are made, directly or indirectly, from corn. Which of the following best summarizes the passage?