As food is pushed along, it undergoes digestion. Digestion is the process of breaking down food into nutrients. There are two types of digestion: mechanical digestion and chemical digestion. Mechanical digestion occurs when large chunks are turned into smaller chucks. Perhaps not surprisingly, this happens when you chew your food. Once you swallow the food, your stomach also does some of this work. Chemical digestion occurs when food is broken down into useful nutrients. This is a chemical process that begins as you start to chew your food. The saliva in your mouth starts this process. Once you swallow, the acid in your stomach further breaks down food. From the stomach, the foods moves into the small intestine. In the small intestines, another set of chemicals goes to work. Are you surprised? Your small intestine, and not your stomach, does most of the work!

What bodily fluids aide in digestion?

Imagine you are standing in a farm field in central Illinois. The land is so flat you can see for miles and miles. On a clear day, you might see a grain silo 20 miles away. You might think to yourself, it sure is flat around here. If you drive one hundred miles to the south, the landscape changes. In southern Illinois, there are rolling hills. Why do you think this is? What could have caused these features? There are no big rivers that may have eroded and deposited this material. The ground is capable of supporting grass and trees, so wind erosion would not explain it. To answer the question, you need to go back 12,000 years. Around 12,000 years ago, a giant ice sheet covered much of the Midwest United States. Springfield, Illinois, was covered by over a mile of ice. Its hard to imagine a mile thick sheet of ice. The massive ice sheet, called a glacier, caused the features on the land you see today. Where did glaciers go? Where can you see them today? Glaciers are masses of flowing ice.

How is the landscape in Southern Illinois different from that in central Illinois?

The highest point of a wave is the crest. The lowest point is the trough. The vertical distance between a crest and a trough is the height of the wave. Wave height is also called amplitude. The horizontal distance between two crests is the wavelength. Both amplitude and wavelength are measures of wave size. The size of an ocean wave depends on how fast, over how great a distance, and how long the wind blows. The greater each of these factors is, the bigger a wave will be. Some of the biggest waves occur with hurricanes. A hurricane is a storm that forms over the ocean. Its winds may blow more than 150 miles per hour! The winds also travel over long distances and may last for many days.
What do we know about wavelength from the paragraph?