1) The world's longest traffic jam occurred in China in 2010 and lasted for 12 days, stretching over 60 miles (97 km).

2) The concept of sovereignty refers to the supreme authority and power of a state to govern itself, make decisions, and control its own territory without interference from external forces.

3) The word "elephant" contains three vowels: E, A, and E.

4) The word "island" contains two vowels: I and A.