1) The Southern Ocean surrounds Antarctica and is the coldest and least-visited ocean.

2) Political campaigns involve strategic activities, such as advertising, public appearances, and grassroots organizing, aimed at promoting a candidate or political party and gaining support during elections.

3) The strongest natural material known to man is spider silk. It is stronger than steel and more flexible than nylon.

4) The name "Bluetooth" comes from the 10th-century Danish king, Harald Bluetooth, who united Denmark and Norway.