1) The sitcom "Friends" is known for its iconic Central Perk coffee shop, where the main characters often gather.

2) 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.

3) The development of voice recognition technology has led to the widespread use of virtual assistants such as Siri, Alexa, and Google Assistant.

4) The Eiffel Tower can be 15 cm taller during the summer due to thermal expansion.