the USA - Hi there!
Germany - Guten tag!
Iran - !أهلا ومرحبا بكم(the above is in Arabic, since I couldn't find a translation into Farsi which is what I think is spoken in Iran. Correct me if I'm wrong, please.)
Ukraine - Привіт і ласкаво просимо!
Australia - G'day! :)
Canada - Hello, or Bonjour (in case you are Quebecois)
Poland - Witam i zapraszam!
If the Ukrainian, Arabic and/or Polish are incorrect, it is the fault of Google Translate. Thank you for visiting, and I hope you'll stick around and become a follower.