In almost every big university (大学)in the U.S.A, football is a favourite sport. American football is not like soccer. Players sometimes kick the hall, but they also throw the ball and run with it. They try to take it to the other end of the field(场地). They have four chances(机会)to move the ball ten yards(码). They can carry it or throw it. If they move it to other end of the field, they receive six points(分). This is called a touchdown(底线得分). It is difficult to move the ball. Eleven men on the team try to stop the man who has the ball. If the man does not move the ball ten yards, his team kicks the ball to the other team. Each university wants its team to win. Thousands of people come to watch. They all yell (喊加油)for their favourite team. Young men and women called cheerleaders (啦啦队长) come to help the people yell more. Each team plays ten or eleven games. Each season begins in September and ends(结束) in November. If a team is very good, it may play another game after the season ends. The best teams play again on January 1, the first day of the New Year. Many people go to see these games and many others watch them on TV. In American football players can ______.