Which country has the highest GPD? which country has the lowest? how big of a difference is there between the two

The yellow river is also known as the huang he river? true or false

The european union was formally established in

Ascientist is explaining how background cosmic radiation gives evidence of the big bang theory. she says that radiation has been detected everywhere equally as heat in the universe and is increasing. this has been shown to be residual radiation from the big bang. what error did the scientist make?