Read the text and fill in the gaps with the appropriate word.

The Arctic Ocean is the ... of the world's five major oceans. The International Depth Institute recognises it as an ... , although some oceanographers call it the Arctic Mediterranean Sea or simply the Arctic Sea. ... general, the Arctic Ocean can be seen as the northernmost part of the World Ocean. Located mostly in the Arctic north ... region in the middle of the Northern Hemisphere, the Arctic Ocean is almost completely surrounded by Eurasia and North America. It is partly covered by sea ... throughout the year and almost completely in winter. The Arctic Ocean's surface temperature varies seasonally as the ice cover melts and freezes; its depth is the lowest on ... of the five major oceans.