![Aerial photo taken on Dec. 21, 2018 shows buildings shrouded in fog in Yangzhou, east China\'s Jiangsu Province. (Xinhua/Meng Delong)](http://www.ecns.cn/hd/2018/12/22/41e977d7106b49e9b253767ea9e1e021.jpg)
Aerial photo taken on Dec. 21, 2018 shows buildings shrouded in fog in Yangzhou, east China's Jiangsu Province. (Xinhua/Meng Delong)
![Aerial photo taken on Dec. 21, 2018 shows buildings shrouded in fog in Yangzhou, east China\'s Jiangsu Province. (Xinhua/Meng Delong)](http://www.ecns.cn/hd/2018/12/22/6b7647d076e74c07b6657929a9c20f45.jpg)
Aerial photo taken on Dec. 21, 2018 shows buildings shrouded in fog in Yangzhou, east China's Jiangsu Province. (Xinhua/Meng Delong)
![Aerial photo taken on Dec. 21, 2018 shows buildings shrouded in fog in Yangzhou, east China\'s Jiangsu Province. (Xinhua/Meng Delong)](http://www.ecns.cn/hd/2018/12/22/ee12942aba464109835fd5f9a1b20a95.jpg)
Aerial photo taken on Dec. 21, 2018 shows buildings shrouded in fog in Yangzhou, east China's Jiangsu Province. (Xinhua/Meng Delong)
![Aerial photo taken on Dec. 21, 2018 shows buildings shrouded in fog in Yangzhou, east China\'s Jiangsu Province. (Xinhua/Meng Delong)](http://www.ecns.cn/hd/2018/12/22/eeb6401278774544a019fe66b430b9f0.jpg)
Aerial photo taken on Dec. 21, 2018 shows buildings shrouded in fog in Yangzhou, east China's Jiangsu Province. (Xinhua/Meng Delong)
![Aerial photo taken on Dec. 21, 2018 shows buildings shrouded in fog in Yangzhou, east China\'s Jiangsu Province. (Xinhua/Meng Delong)](http://www.ecns.cn/hd/2018/12/22/2a100d6ad3f04da1922a3de22ac0c52b.jpg)
Aerial photo taken on Dec. 21, 2018 shows buildings shrouded in fog in Yangzhou, east China's Jiangsu Province. (Xinhua/Meng Delong)