1) The world's largest desert is the Antarctic Desert, covering around 5.5 million square miles.

2) The concept of campaign finance refers to the funding and financial resources required to support political campaigns, including donations from individuals, organizations, and political action committees (PACs).

3) The human brain has a storage capacity equivalent to around 2.5 petabytes, which is roughly equivalent to three million hours of TV shows.

4) The construction of the Great Wall of China began in the 7th century BC and was completed over several centuries, spanning thousands of miles.