ATHENS — Greeks faced shuttered banks and a closed stock market Monday at the beginning of a fateful week that may determine whether they will be able to hold on to the euro currency.The blows from the breakdown in talks between Greece and its creditors also pummeled financial markets. Asian and European exchanges were down sharply, the euro slumped, and Wall Street plummeted, with Greece less than 24 hours away from being unable to pay its bills.Read full article