Script from the WBAP-TV/NBC station in Fort Worth, Texas, relating a news story. Frankfurt, West Germany – The U. S. dollar has opened lower on the Frankfurt open money market. Dollar trading today against the West German mark represents a nearly eight and one-half per cent upward revaluation of the mark. The dollar now has dropped nearly to the trading level registered when President Nixon announced emergency measures to rescue the dollar. Chattanooga, Tennessee – An explosion is reported to have blasted a hole in a portable classroom at a Chattanooga, Tennessee high school. The explosion cause no injuries, but shattered about two dozen windows f a nearby main school building and hurled debris as far as 150 yards. A federal judge has ordered the Chattanooga schools to eliminate segregation. The schools are scheduled to open Tuesday under an order that includes widespread busing. Police say they have no leads in the blast. Bend, Oregon – Search parties planned to comb a central Oregon mountain today for a 15-year-old girl missing and feared dead. Another woman, a 21-year-old Oregon resident, already has been found dead after apparently freezing to death during the graduation exercise of an outdoor survival school. The …