A great example of a physical boundary is a mountain. For example, the Pyrenees Mountains, which serve to separate France and Spain, are a physical boundary. So are the Ural Mountains which separate Europe and Asia. Along with mountains, oceans, seas, even deserts are examples of physical boundaries.
An average size apple weighs 6.4 ounces, which is equal to 180  grams. One apple contains approximately 91 calories and 3 grams of  dietary fiber.
Apple skins contain a great deal of nutrition. Most of an apple's vitamin C content is contained in the skin, as is much of the apple's insoluble fiber content. The skin also contains much of an apple's aroma and flavor. Apples are low in calories, easy to carry, a natural mouth cleaner and an inexpensive snack. A medium sized apple contains 81 calories, 21 grams of carbohydrates and 4 grams of fiber.