ABC News -- Sunlen Miller and Ann Compton Report: President Obama and German Chancellor Angela Merkel sat down in the Oval Office this morning in advance of Merkel's address to a joint session of Congress, which the President dubbed as the "main reason she is here." Merkel will be the first German Chancellor in fifty years to address Congress, and the first Chancellor ever to address a joint session of Congress. "I think a very appropriate honor that has been bestowed on Chancellor Merkel," Obama said with the Chancellor sitting by his side, "we are very pleased that she is going to be here to spread her view of what's taking place in the world and what challenges we face to members of Congress and the American people. The President congratulated...