 Biathlon : Biathlon is a combination of cross @-@ country skiing with target shooting . It requires physical stamina and accurate shooting . The events are open to athletes with physical disabilities and visual impairments . There are fifteen classes in which athletes will be placed depending on their level of function . Twelve divisions are for athletes with a physical impairment and three divisions are for athletes with a visual impairment . The athletes compete together and their finishing times are entered into a formula with their disability class to determine the athletes ' over all finish order . Visually impaired athletes are able to compete through the use of acoustic signals . The signal intensity varies depending upon whether or not the athlete is on target . 
