Aerial photo taken on Sept. 6, 2019 shows a cargo ship of COSCO SHIPPING Lines transporting Italian products to participate in the 2019 China International Import Expo (CIIE) to Shanghai, where the CIIE will be held, berths at the Port of Piraeus, Greece. (Photo by Lefteris Partsalis/Xinhua)

A visitor plays the finger-guessing game with a robot at an exhibition of high technologies and equipment during the fourth China-Arab States Expo in Yinchuan, northwest China's Ningxia Hui Autonomous Region, Sept. 7, 2019. (Xinhua/Feng Kaihua)

A Palestinian protester uses a slingshot to hurl stones at Israeli troops during clashes along the border with Israel, east of the southern Gaza Strip city of Khan Younis, Sept. 6, 2019. (Photo by Khaled Omar/Xinhua)

A model presents a creation from the Vivienne Hu Spring/Summer 2020 collection during the New York Fashion Week in New York, the United States, Sept. 6, 2019 (multiple exposure). (Xinhua/Qin Lang)

Indian Prime Minister Narendra Modi is seen on a TV screen as he watches the live broadcast of the landing process of Chandrayaan-2's Lander Vikram on the moon surface in Bangalore, India, Sept. 7, 2019. India's second Moon mission, Chandrayaan-2's Lander Vikram, lost communication with the ground station at an altitude of 2.1 kilometers from the Lunar surface, said Indian Space Research Organization (ISRO) chief K. Sivan on Saturday. (Str/Xinhua)

A fan of France wearing special glasses cheers up the team during the group L match between France and Lithuania at the 2019 FIBA World Cup in Nanjing, east China's Jiangsu Province, Sept. 7, 2019. (Xinhua/Li Xiang)

German Chancellor Angela Merkel visits Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology in Wuhan, capital of central China's Hubei Province, Sept. 7, 2019. German Chancellor Angela Merkel visited Wuhan on Saturday. (Xinhua/Xiao Yijiu)

Donovan Mitchell (front) of the United States covers his mouth during the group K match between the United States and Greece at the 2019 FIBA World Cup in Shenzhen, south China's Guangdong Province, Sept. 7, 2019. (Xinhua/Xu Chang)

Dennis Schroder of Germany smiles during the group P match between Germany and Senegal at the 2019 FIBA World Cup in Shanghai, east China, on Sept. 7, 2019. (Xinhua/Ding Ting)

Tourists are seen along the Grand Canyon in Arizona, the United States, Aug. 9, 2019. (Xinhua/Li Ying)