Sand dunes are not stationary over time they move. what moves them? in what way do they move?

The sand dune moves by the erosion of the sand from one place to another by means of wind and presipitatipn

Ithink it is space that makes up 70 percent

Historians are researchers of the past or people who understand the history of people. with this field, they must possess qualities such as being unbiased, patient, efficient reader, has a knack for logic and critical thinking and reasoning, disciplined, open-minded, resourceful, with good analytical ability, good reasoning skills and problem solving!