请各位帮忙找一找关于奥运的英语短文

What is "libero1"?

In 1998, the Federation Internationale de Volleyball (FIVB) formally introduced a set of new rules and a new specialist role called the "libero" at a Press Conference in Tokyo. The new set of rules indicate that each team has the option to register one specialized defensive player "libero" among the final list of 12 players for the whole tournament. The libero may not serve, spike the ball over the net, block or attempt to block or rotate into the front-line positions.2 And he/she must wear a different color shirt from the other members of the team. The libero adds an extra dimension to the game by improving the team's reception, lengthening the rallies3, and giving a vital role to shorter players.

1. libero: 自由人，自由球员。

2. serve: 发球; spike: 扣(球)； block: 拦网； front-line position: 前排位置。这句是说“自由人”在场上只能在后排防守，不能进攻或转换至前排。

3. lengthen the rallies: (打球时)延长双方连续对打的次数。rally: 对打，回合。