1) The world's most expensive car is the Bugatti La Voiture Noire, which sold for over $18 million.

2) The Treaty of Versailles, signed in 1919, officially ended World War I and imposed heavy penalties and reparations on Germany.

3) The Edelweiss flower, found in the European Alps, is known for its beauty and is often associated with mountaineering and alpine culture.

4) The concept of proportional representation, used in some electoral systems, aims to ensure that political parties' representation in government aligns more closely with the proportion of votes they receive from the electorate.