Where in the body does the conversion of food into usable energy occur

Our bodies digest the food we eat by mixing it with fluids in the stomach. When our stomach digests the food, the carbohydrate (sugars and starches) in the food breaks down into another type of sugar, called glucose.

Explanation:

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.