Aerial photo taken on June 24, 2019 shows cole flowers in terraced fields in Jishishan County of Linxia Hui Autonomous Prefecture, northwest China's Gansu Province. (Xinhua/Shi Youdong)

Aerial photo taken on June 24, 2019 shows cole flowers in terraced fields in Jishishan County of Linxia Hui Autonomous Prefecture, northwest China's Gansu Province. (Xinhua/Shi Youdong)

Aerial photo taken on June 24, 2019 shows cole flowers in terraced fields in Jishishan County of Linxia Hui Autonomous Prefecture, northwest China's Gansu Province. (Xinhua/Shi Youdong)

Aerial photo taken on June 24, 2019 shows cole flowers in terraced fields in Jishishan County of Linxia Hui Autonomous Prefecture, northwest China's Gansu Province. (Xinhua/Shi Youdong)

Aerial photo taken on June 24, 2019 shows cole flowers in terraced fields in Jishishan County of Linxia Hui Autonomous Prefecture, northwest China's Gansu Province. (Xinhua/Shi Youdong)