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.
These highlands take up the area of nearly half of the country. The Orinoco river is roughly 2,574 kilometers in length and its water drains about four-fifths of the entire country. Venezuela also boasts of over 1,000 rivers, other than the Orinoco.