Help ASAP will give medal & become fan with 2 science question.

1. Every year, Eli and his family visit the Great Sand Dunes desert in Colorado. Eli notices that more sand dunes desert in Colorado. Eli notices that more sand dunes varied shapes and sizes appear each year. Explain what causes this phenomenon.

2. Hannah is comparing a rock from a riverbed and a rock from deep underground. One is very smooth, and the other has very rough edges. Explain why each rock was probably found in that location.

Question

Help ASAP will give medal & become fan with 2 science question.

1. Every year, Eli and his family visit the Great Sand Dunes desert in Colorado. Eli notices that more sand dunes desert in Colorado. Eli notices that more sand dunes varied shapes and sizes appear each year. Explain what causes this phenomenon. 

2. Hannah is comparing a rock from a riverbed and a rock from deep underground. One is very smooth, and the other has very rough edges. Explain why each rock was probably found in that location.