During the summer months，one of the most exciting activities is the yearly Glen Nevis River Race，in which competitors race for three kilometres along the river，but not in a boat.Instead，each competitor uses a lilo，a plastic bed filled with air normally used for camping or floating in the sea，to race along the river.There are rocks，waterfalls and sections with scary names like Dead Dog Pool and the Leg Breaker for them to get through.
Competitors set off at 30 second intervals (间隔) by jumping with their lilos from a tiny shelf on a rock into the fastflowing water 12 metres below.It can take anything from 20 minutes to over two hours to complete the course，depending on the level of the river and the abilities of the competitor.
The only rules are that competitors must be at least 16 years old，and should provide their own crash helmet (防撞头盔)，a rubber wet suit and a life jacket.Gloves and old trainers are suggested to protect against knocks.The most important qualification (资格)，however，is a sense of fun.
The race is full of exciting moments，and the greatest of these is at the Lower Falls Leap，where terrified competitors have to jump over a tenmetre waterfall not far from the finish.More than 3,000 athletes have taken part in the race during its 30year history.Their ￡30 entry fee helps to raise money for the mountain rescue team，whose members provide an essential service in the region for free.
The prizes may not be fantastic，but everyone receives a certificate (证书) of completion and the winner gets the title River Race Champion and all who take part agree that it is worth it for the satisfying feeling of reaching the end safely.
语篇解读 本文是说明文。文章主要介绍了苏格兰的格伦尼维斯河比赛。
5．What do we know about the Glen Nevis River Race?
A．It is usually held in winter.
B．Its winners receive grand prizes.
C．It is interesting though quite difficult.
D．Its participants have to swim for 3 km.
解析： 推理判断题。由第二段中的one of the most exciting activities和There are rocks，waterfalls...the Leg Breaker for them to get through可知，格伦尼维斯河比赛难度很大，但也有趣。
答案： C
6．According to the text, to complete the race， .
A．the competitors' abilities matter
B．the quality of the lilos plays a key role
C．the level of the river does not matter much