Polycystic Ovarian Disease: This disease, also commonly known as PCOS, refers to cysts that form from a buildup of follicles. They cause the ovaries to enlarge and create a thick outer covering, which may prevent ovulation from occurring. They are often the cause of fertility problems.
dune. n. A hill or ridge of wind-blown sand. [French, from Old French, from Middle Dutch. ; see dheuÉ- in Indo-European roots .].
An oasis is a hub of water in the desert, often in the form of springs, wells, or irrigation systems. About 75 percent of the Saharaâs population lives in oases, which make up only 2,071 square kilometers of the desertâs vast area. A sand dune is a mountain of sand. Some dunes can be as high as 600 feet.