"observation is the test of scientific truth. so far, observations of the earth's temperature has not revealed signs of a human-induced global warming." -- george c. marshall institute, 1997 which of the following statements best reflects and agrees with the quote? a scientists disagreed on whether human activity had a significant impact on earth's temperature. b studies have proven that industrialization has had no measurable impact on the environment. c recent laws were successful in limiting the long-term effects of industrialization on the earth. d researchers have not found evidence humans cause or control earth's temperature changes.