American football

肆叁零

American football is a sport played by two teams of eleven players on a rectangular field with goalposts at each end. The offense， the team with control of the football （an oval-shaped ball）， attempts to advance in the field by running with or passing the ball， while the team without control of the ball， the defense， aims to stop their advance and take control of the ball for themselves. The offense must advance at least ten yards in four downs， or else they will turn over the football to the other team； if they succeed， they are given a new set of four downs. Points can be scored by advancing the ball into the other teams end zone for a touchdown， kicking the ball through the opponents goalposts for a field goal， or tackling the ball carrier in his own end zone for a safety. The team with the most points at the end of a game wins.

美式足球是一種由每隊十一個球員組成的兩支隊伍，在末端各有兩支球門柱的矩形場競技的體育運動。進攻方，控制橄欖球的隊伍（一個橢圓形的球），試圖在比賽中用運球和傳球的方式推進；而沒有控球權的隊伍，即防守方，旨在阻止他們推進，并搶回控球權。進攻方必須在四次進攻機會中推進至少十碼，否則他們將轉交控球權給對方；如果他們成功了，他們將獲得一套新的四次進攻機會。獲得分數的方式有將球推進至對方隊伍的端區達陣得分，將球踢過對方兩支球門柱的中間射門得分，或者在持球者的端區攔截成功安防得分。在比賽結束時得分最多的隊伍獲勝。

American football is the most popular sport in the United States. Professional football and college football are the most popular forms of the game， with the other major levels being high school and youth football. As of 2012， nearly 1.1 million high school athletes and 70，000 college athletes play the sport in the United States. The National Football League， the most popular American football league， has the highest average attendance of any sports league in the world； its championship game， the Super Bowl， ranks among the most-watched club sporting events in the world， and the league has a revenue of around $10 billion every year.

美式足球是美國最流行的體育運動。職業橄欖球和大學橄欖球都是最流行的比賽形式，高中橄欖球和青少年橄欖球則是另一個重要層次。在2012年的時候，美國有近一百一十萬名高中運動員和七萬名大學生運動員參與這項運動。國家橄欖球聯盟，美國最受歡迎的橄欖球聯賽，享有世界上所有體育聯賽的最高平均出席率；它的總決賽，超級碗，是世界上最受關注的俱樂部體育賽事，并且聯盟每年的年收入約為十億美元。