French frontrunner could prove difficult partner for Merkel

By Noah Barkin BERLIN (Reuters) - In 2007, on his first visit to Berlin as French prime minister, Francois Fillon gave Angela Merkel an antique edition of "Radioactivity", a work by one of her heroes, fellow physicist Marie Curie. The book, now prominently displayed in the Chancellery in Berlin, is a symbol of Franco-German friendship and a reminder that Fillon, favorite to win the French presidency after his resounding victory in the first round of the Republican primary on Sunday, is a known q