DETROIT, Mich (WLMI) General Motors posted a $510 million dollar profit in the fourth quarter of 2010 and a $4.7-billion dollar profit for the year in an impressive comeback from bankruptcy.  GM Chairman and CEO Dan Ackerson made the announcement Thursday morning and says the company is continuing to work hard and reduce its debt.  The profits were fueled by strong sales in China and the U-S as the global auto market began to recover.