Hot air balloons are seen in the sky during the annual Canberra Balloon Spectacular festival in Canberra, Australia, March 8, 2021. The annual Canberra Balloon Spectacular festival, a hot air balloon festival celebrated in Australia's capital city, is held this year from March 6 to 14. (Photo by Liu Changchang/Xinhua)

Hot air balloons are seen in the sky during the annual Canberra Balloon Spectacular festival in Canberra, Australia, March 10, 2021. The annual Canberra Balloon Spectacular festival, a hot air balloon festival celebrated in Australia's capital city, is held this year from March 6 to 14. (Photo by Liu Changchang/Xinhua)

Hot air balloons are seen in the sky during the annual Canberra Balloon Spectacular festival in Canberra, Australia, March 8, 2021. The annual Canberra Balloon Spectacular festival, a hot air balloon festival celebrated in Australia's capital city, is held this year from March 6 to 14. (Photo by Liu Changchang/Xinhua)

Hot air balloons are seen in the sky during the annual Canberra Balloon Spectacular festival in Canberra, Australia, March 8, 2021. The annual Canberra Balloon Spectacular festival, a hot air balloon festival celebrated in Australia's capital city, is held this year from March 6 to 14. (Photo by Liu Changchang/Xinhua)