There are relay RACES in running... in summer. 2 There are relay in skiing in winter.
夏季有赛跑和游泳赛接力赛，冬季有滑雪比赛。
2
For these small groups, there are relay RACES in running and swimming in summer, and relays in skiing in winter.
对于这些小的组，就是夏季奥运会上的跑步接力赛和游泳接力赛，冬季奥运会上的滑雪接力赛。
3
No running RACES or horse riding are included. There are events like skiing and ice skating which need snow and ice. That is why they are called the Winter Olympics.