Depo Provera is considered a very effective method of birth control. If taken every thirteen weeks, it is estimated to be 99% effective. It does not, however, protect a woman from STDs. Studies indicate that women on Depo have a decreased risk of ovarian cancer, Pelvic Inflammatory Disease, and Endometrial Cancer.
The Orinoco is one of the longest rivers in South America at 2,140 kilometres (1,330 mi). Its drainage basin, sometimes called the Orinoquia, covers 880,000 square kilometres (340,000 sq mi), with 76.3 percent of it in Venezuela and the remainder in Colombia.
Typical region in the Okavango Delta, with free canals and lakes, swamps and islands. The Okavango Delta (or Okavango Grassland) (formerly spelled Okovango or Okovanggo) in Botswana is a very large, swampy inland delta formed where the Okavango River reaches a tectonic trough in the central part of the endorheic basin of the Kalahari.