Discuss why obesity is a growing epidemic.

Americans don't get much exercise, but in fact, they need to exercise at least an hour a day to stay healthy, according to guidelines issued in September 2002 by the National Institute of Medicine. Members of a 21-person panel that issued the guidelines said they were concerned about the jump in obesity rates over the last few decades. According to the American Heart Association (AHA), all healthy adults should be getting at least 30 minutes of moderate intensity exercise five days a week. Modern conveniences keep people from the activities they need to stay in shape.  

Many people like to blame fast food, but Bill Gates is probably as much to blame as Ronald McDonald. In fact, just about every aspect of our society actively contributes to the epidemic. A bunch of little things have dramatically tipped the scales. And in the case of the American waistline, little things can add up to something very large. Obesity has been directly linked to heart disease, high blood pressure, stroke, and type 2 diabetes and may set the stage for a host of other illnesses. In fact, American Cancer Society researchers estimate that obesity accounts for about one-third of all cancer deaths in this country.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

layer 3 is younger than layer 6.