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 word "telephone" contains five vowels: E, E, O, E, and E.

3) The world's largest diamond, the Cullinan, was discovered in South Africa in 1905 and weighed over 3,000 carats.

4) The largest known dinosaur, Argentinosaurus, weighed around 70-100 tons and measured up to 100 feet in length.