A staff worker takes picture of a giant pumpkin at a greenhouse in Changchun, capital of northeast China's Jilin Province, July 9, 2019. The 18th Changchun Agriculture and Food Expo will kick off here on Aug. 16. The giant pumpkins at the Changchun Agri-Expo Garden, which are expected to grow up to 500 kilograms by the opening of the expo, will be exhibited during the expo.(Photo: Xinhua)

A staff worker takes care of giant pumpkins at a greenhouse in Changchun, capital of northeast China's Jilin Province, July 9, 2019. The 18th Changchun Agriculture and Food Expo will kick off here on Aug. 16. The giant pumpkins at the Changchun Agri-Expo Garden, which are expected to grow up to 500 kilograms by the opening of the expo, will be exhibited during the expo.(Photo: Xinhua)

A staff worker checks the condition of a giant pumpkin at a greenhouse in Changchun, capital of northeast China's Jilin Province, July 9, 2019. The 18th Changchun Agriculture and Food Expo will kick off here on Aug. 16. The giant pumpkins at the Changchun Agri-Expo Garden, which are expected to grow up to 500 kilograms by the opening of the expo, will be exhibited during the expo.(Photo: Xinhua)

A staff worker takes care of a giant pumpkin at a greenhouse in Changchun, capital of northeast China's Jilin Province, July 9, 2019. The 18th Changchun Agriculture and Food Expo will kick off here on Aug. 16. The giant pumpkins at the Changchun Agri-Expo Garden, which are expected to grow up to 500 kilograms by the opening of the expo, will be exhibited during the expo.(Photo: Xinhua)

A staff worker takes care of giant pumpkins at a greenhouse in Changchun, capital of northeast China's Jilin Province, July 9, 2019. The 18th Changchun Agriculture and Food Expo will kick off here on Aug. 16. The giant pumpkins at the Changchun Agri-Expo Garden, which are expected to grow up to 500 kilograms by the opening of the expo, will be exhibited during the expo. (Photo: Xinhua)

A staff worker checks the condition of a giant pumpkin at a greenhouse in Changchun, capital of northeast China's Jilin Province, July 9, 2019. The 18th Changchun Agriculture and Food Expo will kick off here on Aug. 16. The giant pumpkins at the Changchun Agri-Expo Garden, which are expected to grow up to 500 kilograms by the opening of the expo, will be exhibited during the expo. (Photo: Xinhua)