Sand is used extensively in the manufacture of bricks, mortar, cement, concrete, and plaster. However, perhaps its most well-known use as a building material is in sand castles. A common sight on beaches and sandboxes, simple sand castles require just a few tools and ingredients: a shovel, a bucket, water, and, of course, sand. Some more advanced sand sculptors use the “dripping” technique—dribbling wet sand down onto the castle foundation to form towers. Why does water make sand stick together? Discuss