1) International relations encompass the study of relationships between nations, including diplomacy, treaties, and foreign policy. It examines the interactions and dynamics among different countries in the global arena.

2) The increasing emphasis on mental health and well-being has led to greater awareness, advocacy, and destigmatization of mental health issues, as well as efforts to improve access to mental health services and support systems.

3) The musical "The Phantom of the Opera" has been running in London's West End since 1986, making it the longest-running musical in history.

4) The ocean covers about 71% of the Earth's surface and contains roughly 97% of the planet's water.