China's polar icebreaker Xuelong 2 breaks ice in the waters in Antarctica, Nov. 22, 2019. (Xinhua/Liu Shiping)

China's polar icebreaker Xuelong (back) follows the other icebreaker Xuelong 2 towards the designated unloading area near the Zhongshan Station in Antarctica, Nov. 23, 2019. (Xinhua/Liu Shiping)

China's polar icebreaker Xuelong 2 breaks ice in the waters in Antarctica, Nov. 22, 2019. (Xinhua/Liu Shiping)

The helicopter unloads cargos from China's polar icebreaker Xuelong in the waters in Antarctica, Nov. 23, 2019. (Xinhua/Liu Shiping)

China's polar icebreaker Xuelong 2 breaks ice in the waters in Antarctica, Nov. 22, 2019. (Xinhua/Liu Shiping)

China's polar icebreaker Xuelong 2 breaks ice in the waters in Antarctica, Nov. 22, 2019. (Xinhua/Liu Shiping)

China's polar icebreaker Xuelong 2 breaks ice in the waters in Antarctica, Nov. 22, 2019. (Xinhua/Liu Shiping)