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) Aztec mythology, originating from ancient Mesoamerica, includes deities like Quetzalcoatl, Huitzilopochtli, and Tlaloc. It explores concepts of creation, sacrifice, and the cyclical nature of time, with intricate cosmology and rituals forming a significant part of Aztec religious beliefs and practices.

3) The novel "To Kill a Mockingbird" by Harper Lee has been translated into more than 40 languages and has sold over 40 million copies worldwide.

4) The world's largest ocean, the Pacific Ocean, covers an area of approximately 63 million square miles.