By The Associated PressMETALS SLUMP: Gold, silver, copper, platinum and palladium all declined after the head of the European Central Bank expressed concern over the rise in the euro. That prompted the currency to weaken and the dollar to rally. Commodities are typically traded in dollars, so when the currency strengthens, traders demand fewer dollars. That pushes down commodity prices. PALLADIUM LEADS PACK: Palladium was the biggest loser, declining 1.9 percent to $750.45 an ounce. That was the biggest drop for the metal in a month. CORN FALL: Corn declined for a fifth day, dropping 1.6 percent to $7.1075 a bushel, its lowest level in a month.