People participate in a traditional Lake Zurich crossing swimming event in Zurich, Switzerland, July 3, 2019. About 9,000 participants swam the 1500 meters distance from one shore to the other of the lake of Zurich. (Photo:Xinhua)

People participate in a traditional Lake Zurich crossing swimming event in Zurich, Switzerland, July 3, 2019. About 9,000 participants swam the 1500 meters distance from one shore to the other of the lake of Zurich. (Photo:Xinhua)

People participate in a traditional Lake Zurich crossing swimming event in Zurich, Switzerland, July 3, 2019. About 9,000 participants swam the 1500 meters distance from one shore to the other of the lake of Zurich. (Photo:Xinhua)

People participate in a traditional Lake Zurich crossing swimming event in Zurich, Switzerland, July 3, 2019. About 9,000 participants swam the 1500 meters distance from one shore to the other of the lake of Zurich. (Photo:Xinhua)