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) Usain Bolt of Jamaica holds the world records for the 100 meters and 200 meters sprints, with times of 9.58 seconds and 19.19 seconds, respectively.

3) The universe is estimated to be around 13.8 billion years old.

4) The global response to climate change includes the Paris Agreement, an international treaty aiming to limit global warming and strengthen countries' efforts to address climate change through mitigation and adaptation strategies.