A herdsman drives horses on a grassland in Hexigten Qi of Chifeng City, north China's Inner Mongolia Autonomous Region, June 30, 2018. (Xinhua/Peng Yuan)

A herdsman drives horses on a grassland in Hexigten Qi of Chifeng City, north China's Inner Mongolia Autonomous Region, June 29, 2018. (Xinhua/Yu Dongsheng)

A herdsman drives horses on a grassland in Hexigten Qi of Chifeng City, north China's Inner Mongolia Autonomous Region, June 29, 2018. (Xinhua/Yu Dongsheng)

A herdsman drives horses on a grassland in Hexigten Qi of Chifeng City, north China's Inner Mongolia Autonomous Region, June 29, 2018. (Xinhua/Peng Yuan)

Herdsmen drive horses on a grassland in Hexigten Qi of Chifeng City, north China's Inner Mongolia Autonomous Region, June 30, 2018. (Xinhua/Yu Dongsheng)

Herdsmen drive horses on a grassland in Hexigten Qi of Chifeng City, north China's Inner Mongolia Autonomous Region, June 29, 2018. (Xinhua/Yu Dongsheng)

Herdsmen drive horses on a grassland in Hexigten Qi of Chifeng City, north China's Inner Mongolia Autonomous Region, June 30, 2018. (Xinhua/Peng Yuan)

Herdsmen drive horses on a grassland in Hexigten Qi of Chifeng City, north China's Inner Mongolia Autonomous Region, June 29, 2018. (Xinhua/Peng Yuan)

Herdsmen drive horses on a grassland in Hexigten Qi of Chifeng City, north China's Inner Mongolia Autonomous Region, June 30, 2018. (Xinhua/Peng Yuan)

Herdsmen drive horses on a grassland in Hexigten Qi of Chifeng City, north China's Inner Mongolia Autonomous Region, June 29, 2018. (Xinhua/Yu Dongsheng)

Herdsmen drive horses on a grassland in Hexigten Qi of Chifeng City, north China's Inner Mongolia Autonomous Region, June 30, 2018. (Xinhua/Yu Dongsheng)