听力原文： Tennis is an international sport and each year there is a regular program of tournaments and championships. Players' performance in these events determines their seeding, or world ranking. If you play or are interested in tennis it's always a good idea to watch the professionals in action. You'll start to see how they use tactics to outplay their opponents. It is also interesting to see how play differs on different court surfaces. Some players prefer the slow game of the clay courts, others excel at the high-speed play of the grass court. Tennis has four 'Grand Slam' Tournaments. These are the main world events, perhaps the greatest tournaments in sport attracting the world's finest players. The Grand Slam events are: the Australian Open—Melbourne, January the French Open—Paris, June the Wimbledon Championships—Wimbledon, June/July and the US Open—New York, September. Other top tennis tournaments are: the ATP Tour, WTA Tour, the Hopman Cup, the Davis Cup and the Masters Series. The Lawn Tennis Championships at Wimbledon was first played in 1877, witnessed by only a few hundred spectators. Now this highly professional tournament attracts an audience of 500,000 and through the press, radio, Internet and television a following of millions throughout the world. The Tournament starts each year six weeks before the first Monday in August and lasts for a fortnight or for as long as necessary to complete all events. (31)