1) The FIFA World Cup is the most-watched sporting event globally, with billions of viewers tuning in for the tournament held every four years.

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

3) Sourdough bread is a type of bread made through a fermentation process that involves wild yeast and lactic acid bacteria. It has a distinct tangy flavor and a chewy texture. Sourdough bread is often considered healthier than conventional bread due to its potential benefits for digestion and nutrient absorption. It has gained popularity in recent years, with artisanal bakeries and home bakers reviving the traditional art of sourdough baking.

4) Mountains are important water sources, as they capture and store precipitation, feeding rivers and supporting ecosystems downstream.