A ground-breaking report written by a major group of scientists has indicated that much of the previously untraceable pollutants in stream water known to kill fish and harm humans comes from polluted rain water and irresponsible chemical dumping by large corporations.

• A. many of the previously untraceable pollutants in stream water known to kill fish and harm humans come from
• B. much of the previously untraceable pollutants in stream water known to kill fish and harm humans come from
• C. many of the previously untraceable pollutants in stream water known to kill fish and harm humans comes from
• D. much of the previously untraceable pollutants in stream water known to kill fish and harming humans come from