American football is called soccer, but it's not the same to football. It's an American national sport.
There are eleven players in a team. It's mainly (主要地) played by holding or throwing the ball. Some people may feel that American football is a brutal (粗暴的) sport. In fact, it's a popular competitive (竞赛) sport in America. The game also has the very high fever in the American university (大学) student community. It's one of their hobbies.
