Volunteers visit China's first domestically built polar icebreaker "Xuelong 2," or "Snow Dragon 2," upon its arrival at a port in Shenzhen, south China's Guangdong Province, Oct. 13, 2019. "Xuelong 2" will sail for Antarctica on its maiden voyage on Oct. 15, 2019, together with another Chinese icebreaker "Xuelong", in the country's 36th research mission to the region. (Xinhua/Mao Siqian)