A、4. B、5. C、6. D、7. B推理判断题。本题问的是接力比赛时一个队有几名溜冰选手参加。短文中提到，每个团队的四名主力和一名替补参加溜冰接力比赛，共八个团队。即每个团队有五名选手参加溜冰接力比赛。

Short track speed skating is only about 100 years old and a product of North America.(22)It originated in Canada and the United States in 1905 with the first known competition having taken place in 1909. By the 1920s and 30s, the sport was gaining popularity in Great Britain, Japan, France, Belgium and Australia. In 1988, short track speed skating was a demonstration event at the Calgary Olympic Winter Games.(23)Four years later, it was included as an official event at the Albertville 1992 Olympic Winter Games. Short track speed skating takes place on a 111. 12-meter oval track within a hockey rink. Tight corners make it difficult for skaters to maintain control. Skaters compete against each other, rather than the clock. The competition consists of a series of heats with four or six athletes. The first two athletes in each heat advance to the next round until only four skaters remain for the final. The men’s and ladies’ short track relays take place over two days and consist of semi-final and final competitions.(24)Eight teams of four skaters plus a substitute take part in the relay. The teams decide how many laps each of their members will race, with the understanding that the final two laps must be covered by the same skater. It is unusual for an individual athlete to exceed 1. 5 laps, meaning there are some seven or eight relay exchanges per athlete. Instead of passing a baton(接力棒), the skater on the ice needs to only tag the next skater to complete an exchange. In order to maintain momentum,(25)however, it is more common for the next skater to crouch and receive a push from behind.
22. Where did short track speed skating come from?
23. When did short track speed skating become the official Olympic event?
24. How many skaters on one team take part in the relay?
25. How do the skaters complete an exchange in a relay?