Giant panda Wang Wang is on its way to the pool during its birthday party in Adelaide Zoo, Adelaide, Australia, on Aug. 25, 2019. The tenth birthday overseas of the two pandas, Wang Wang and Fu Ni, was celebrated Sunday in Adelaide Zoo, the second oldest zoo in Australia, boasting a history of more than 130 years with more than 2,500 animals. (Photo: Xinhua)

Panda Wang Wang is on its way to the pool during its birthday party in Adelaide Zoo, Adelaide, Australia, on Aug. 25, 2019. The tenth birthday overseas of the two pandas, Wang Wang and Fu Ni, was celebrated Sunday in Adelaide Zoo, the second oldest zoo in Australia, boasting a history of more than 130 years with more than 2,500 animals. (Photo: Xinhua)

Panda Wang Wang is on its way to the pool during its birthday party in Adelaide Zoo, Adelaide, Australia, on Aug. 25, 2019. The tenth birthday overseas of the two pandas, Wang Wang and Fu Ni, was celebrated Sunday in Adelaide Zoo, the second oldest zoo in Australia, boasting a history of more than 130 years with more than 2,500 animals. (Photo: Xinhua)

Giant panda Wang Wang is on its way to the pool during its birthday party in Adelaide Zoo, Adelaide, Australia, on Aug. 25, 2019. The tenth birthday overseas of the two pandas, Wang Wang and Fu Ni, was celebrated Sunday in Adelaide Zoo, the second oldest zoo in Australia, boasting a history of more than 130 years with more than 2,500 animals. (Photo: Xinhua)

Panda Wang Wang is on its way to the pool during its birthday party in Adelaide Zoo, Adelaide, Australia, on Aug. 25, 2019. The tenth birthday overseas of the two pandas, Wang Wang and Fu Ni, was celebrated Sunday in Adelaide Zoo, the second oldest zoo in Australia, boasting a history of more than 130 years with more than 2,500 animals. (Photo: Xinhua)

Giant panda Fu Ni rests during its birthday party in Adelaide Zoo, Adelaide, Australia, on Aug. 25, 2019. The tenth birthday overseas of the two pandas, Wang Wang and Fu Ni, was celebrated Sunday in Adelaide Zoo, the second oldest zoo in Australia, boasting a history of more than 130 years with more than 2,500 animals. (Photo: Xinhua)

Giant panda Wang Wang tries to open its gift box during its birthday party in Adelaide Zoo, Adelaide, Australia, Aug. 25, 2019. The tenth birthday overseas of the two pandas, Wang Wang and Fu Ni, was celebrated Sunday in Adelaide Zoo, the second oldest zoo in Australia, boasting a history of more than 130 years with more than 2,500 animals. (Photo: Xinhua)

Giant panda Wang Wang tries to open its gift box during its birthday party in Adelaide Zoo, Adelaide, Australia, Aug. 25, 2019. The tenth birthday overseas of the two pandas, Wang Wang and Fu Ni, was celebrated Sunday in Adelaide Zoo, the second oldest zoo in Australia, boasting a history of more than 130 years with more than 2,500 animals. (Photo: Xinhua)