1) The world's first credit card was introduced in 1950 by Diners Club.

2) Political campaigns involve strategic activities, such as advertising, public appearances, and grassroots organizing, aimed at promoting a candidate or political party and gaining support during elections.

3) The concept of federalism involves the division of powers between a central government and regional or local governments, allowing for shared governance and autonomy for different levels of administration.

4) The largest living structure on Earth is the Great Barrier Reef, spanning over 2,300 kilometers (1,400 miles) along the coast of Australia.