Hot air balloons are seen in the sky during the hot air balloon festival "Balloons over Waikato" in Hamilton, New Zealand, March 18, 2020. Balloons over Waikato is held in Hamilton annually, attracting balloonists from all over New Zealand and around the world. (Photo by Zhu Xi/Xinhua)

Hot air balloons are seen in the sky during the hot air balloon festival "Balloons over Waikato" in Hamilton, New Zealand, March 18, 2020. Balloons over Waikato is held in Hamilton annually, attracting balloonists from all over New Zealand and around the world. (Photo by Zhu Xi/Xinhua)

Hot air balloons are seen in the sky during the hot air balloon festival "Balloons over Waikato" in Hamilton, New Zealand, March 18, 2020. Balloons over Waikato is held in Hamilton annually, attracting balloonists from all over New Zealand and around the world. (Photo by Zhu Xi/Xinhua)