1) The fall of the Berlin Wall in 1989 symbolized the end of the Cold War and the reunification of East and West Germany.

2) The Yangtze River, also known as the Changjiang River, is the longest river in Asia and the third-longest in the world, stretching over 6,300 kilometers (3,915 miles). It holds immense cultural, historical, and ecological significance for China and the surrounding regions.

3) 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.

4) The Himalayas, known as the "Roof of the World," are home to numerous majestic peaks, cultural diversity, and unique wildlife.