| 1 | The Arctic Ocean is covered by sea ice for most of the year. | |
| 2 | Antarctic krill is one of the important organisms in the Southern Ocean of Antarctica. | |
| 3 | One of the navy's missions is to maintain the country's maritime security. | |
| 4 | Biodiversity is very important in marine ecosystems. | |
| 5 | Researchers have discovered new species of marine life on the ocean floor. |
Copyright © Purple Culture Co., Ltd. 2001 - 2026. All right reserved.
