Rafting is a team sport, in which all the crew members in the boat row and position themselves in a coordinated manner in order to balance their weight when going through the river rapids and keep themselves afloat.
The standard number of people allowed on the boat is from six to eight crew members, depending on the boat size.
Rafting beginners are recommended to remain in the center of the boat. Those who are somehow experienced and prefer to row may stay in front, whereas the most experienced generally stay at the back.
Approximately 65 million years ago, a large percentage of vegetables and animals suddenly became extinct. It was in the late Cretaceous period and there are various theories about it. Some scientists attribute this event to a gradual process that finally led to selective extinction. Others assert that a catastrophe, such as an asteroid hitting the Earth, caused these species mass extinction.