premise: In 1982, for example, RCED examined the progress made since the 1970's in cleaning up the nation's air, water, and land, finding that while strides had been made toward meeting the established goals (cleaner air, properly treated wastewater, more drinkable water), deadlines had been extended and unresolved issues made meeting even these deadlines difficult (U.S.
hypothesis: Since 1970 no progress has been made in cleaning the nation's air.