instruction:
Given an trivia question precisely answer the question with a word/phrase/name. External resources such as Wikipedia could be used to obtain the facts.
question:
Romania and which other country joined the EU on the 1st January 2007?
answer:
bulgaria


question:
Which country does tennis player Marcelo Rios come from?
answer:
chile


question:
The Hanseatic League was a union of ports on which sea?
answer:

baltic sea