China’s central bank cut interest rates on Friday for the sixth time in less than a year, and it again lowered the amount of cash that banks must hold as reserves in a bid to jump start growth in its stuttering economy. Monetary policy easing in the world’s second-largest economy is at its most aggressive since the 2008/09 financial crisis, as growth looks set to slip to a 25-year-low this year of under 7 percent.