What is the capital of the Pitcairn Islands?

What is the capital of the Northern Mariana Islands? What is the capital of Guam? Which city is the capital of the Federated States of Micronesia? Which city is the capital of Wallis and Futuna? What is the capital of American Samoa? What is the longest river in Asia? What is the longest river in Africa? What is the longest river in Europe?