The diagrams below show how sand dunes are formed. Summarize the information by selecting and reporting the main features, and make comparisons where relevant.

The illustration shows the process of how sand dunes are formed. In general, dunes appear when wind moves sand and drops it in some places. Step by step, the sand builds up and becomes higher. At first, the wind blows and carries dry sand particles. Some of them stop on wet sand because they are […]