Swiss Air Force aerobatic team "Patrouille Suisse" stages a performace to mark the ongoing 3rd Winter Youth Olympic Games, at Les Diablerets Alpine centre, Switzerland on Jan. 11, 2020. (Xinhua/Wang Qingqin)

Swiss Air Force aerobatic team "Patrouille Suisse" stages a performace to mark the ongoing 3rd Winter Youth Olympic Games, at Les Diablerets Alpine centre, Switzerland on Jan. 11, 2020. (Xinhua/Wang Qingqin)

Swiss Air Force aerobatic team "Patrouille Suisse" stages a performace to mark the ongoing 3rd Winter Youth Olympic Games, at Les Diablerets Alpine centre, Switzerland on Jan. 11, 2020. (Xinhua/Wang Qingqin)

Swiss Air Force aerobatic team "Patrouille Suisse" stages a performace to mark the ongoing 3rd Winter Youth Olympic Games, at Les Diablerets Alpine centre, Switzerland on Jan. 11, 2020. (Xinhua/Wang Qingqin)