Answer:
meteorite striking the dinosaures
Between 1962 and 1971, the United States Army Corps of Engineers (USACE) channeled the Kissimmee River and created a 30-foot deep, 300-foot wide, 56 mile long drainage canal (C-38). This project converted 44% of the floodplain to pasture, draining approximately 31,000 acres of wetlands. Before channelization, the River was a haven for wildlife, including at least 39 species of fish and 38 species of water birds.
Kissimmee River Restoration began in 1992 and has been the most successful ecosystem restoration initiative to date. By re-channelizing the River to replicate its natural paths, birds and other wildlife responded more quickly than anticipated and demonstrated the resiliency of nature. This success has been used all over the world to justify the value of ecosystem restoration. When Kissimmee River Restoration is completed in 2015, more than 40 square miles of the River-floodplain ecosystem will be restored, including almost 20,000 acres of wetlands and 44 miles of historic river channel.
The classical astronomers concluded that heavens were made up of a sphere, because heavens were thought to be perfect and spheres (circles) are a perfect shape. It was Plato who argued that geometrical figures were spheres and everyone agreed to him. It was also believed that the perfect motion of spheres was a uniform circular rotation.
