A man watches tomato products during the 7th Ningxia Seeds Expo held at Pingluo County of Shizuishan City, northwest China's Ningxia Hui Autonomous Region, July 27, 2020. (Xinhua/Wang Peng)

Participants learn about seed products during the 7th Ningxia Seeds Expo held at Pingluo County of Shizuishan City, northwest China's Ningxia Hui Autonomous Region, July 27, 2020. (Xinhua/Wang Peng)

Participants learn about seed products during the 7th Ningxia Seeds Expo held at Pingluo County of Shizuishan City, northwest China's Ningxia Hui Autonomous Region, July 27, 2020. (Xinhua/Wang Peng)

Participants learn about corn seed products during the 7th Ningxia Seeds Expo held at Pingluo County of Shizuishan City, northwest China's Ningxia Hui Autonomous Region, July 27, 2020. (Xinhua/Wang Peng)