Photo taken on Oct. 31, 2016 shows the engine room of 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 engine room of 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)