31. Sand dunes in the desert are caused by erosion.fiom -(2006-9) a. rain b. glaciers c. streams d. wind

Sand dunes in the desert are primarily shaped by the persistent force of the wind, which transports sand particles from one place to another. Over time, this wind action creates the iconic, rippling forms of sand dunes that are often found in arid environments. The combination of wind strength and sand availability is essential to the development of these fascinating landforms. In certain regions, dunes can grow to impressive heights and can even shift over time, altering the landscape as they move. The study of sand dunes not only provides insight into geological processes but also helps scientists understand how ecosystems adapt to changing environments, making it a crucial topic in both geography and environmental science.