Photo taken on Oct. 31, 2016 shows the "Polaris" icebreaker in Helsinki, Finland. Finland operated the world's first icebreaker powered by liquefied natural gas in Helsinki on Tuesday. (Xinhua/Li Jizhi)
Photo taken on Oct. 31, 2016 shows the "Polaris" icebreaker in Helsinki, Finland. Finland operated the world's first icebreaker powered by liquefied natural gas in Helsinki on Tuesday. (Xinhua/Li Jizhi)