1) The Earth's core is primarily composed of iron and nickel and is as hot as the surface of the sun.

2) The Tour de France, first held in 1903, is one of the most prestigious and grueling cycling races, covering over 3,500 kilometers (2,200 miles) in three weeks.

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 Paralympic Games, held immediately after the Olympic Games, showcase the athletic abilities of individuals with disabilities and promote inclusivity in sports.