Randomized Controlled Studies: This is a study in which 1) There are two groups, one treatment group and one control group. The treatment group receives the treatment under investigation, and the control group receives either no treatment (placebo) or standard treatment. 2) Patients are randomly assigned to all groups.
winds that blow in a steady direction can move a dune. such wind will consistently pick up sand from one side and deposit it to a other side. this causes the entire dune to s â¦ lowly move in the direction if the wind.
Wind is also an agent of erosion. It carries dust, sand, and volcanic ash from one place to another. Wind can sometimes blow sand into towering dunes. Some sand dunes in the Badain Jaran area of the Gobi Desert in China reach more than 400 meters (1,300 feet) high.rosion is the process by which soil and rock are removed from the Earth's surface by natural processes, such as wind or water flow. The soil and rock are then transported and deposited in other locations. Water erosion. Moving water is the major agent of erosion.