Prices continue to tumble. - As with oil, prices for raw materials are continuing the headlong fall which started at the beginning of the second quarter. The Dow Jones UBS composite index, which covers such things as oil, copper and cotton prices, has fallen 9% since the end of February. Cotton has fallen by 22% since the beginning of the year, steel in the United States by 13% in two months and 9% in one month in China. This downward trend reflects economists' concern over growth in China,...