【简答题】Lead(铅) deposits, which accumulated(增加) in soil and snow during the 1960's and 70's, were primarily the result of leaded gasoline emissions originating in the United States. In the twenty years that t...
【单选题】Lead deposits, which accumulated in soil and snow during the 1960's and 70's, were primarily the result of leaded gasoline emissions originating in the United States. In the twenty years that the Clea...
A.
the Clean Air Act has not produced the desired results.
B.
lead deposits in arctic snow on the increase.
C.
lead will stay in soil and snow longer than expected.
D.
the U.S. is the major source of lead pollution in arctic snow.
【单选题】Lead deposits, which accumulated in soil and snow during the 1960's mid 7O's, were primarily the result of leaded gasoline emissions originating in the United States. In the twenty years that the Clea...
A.
the Clean Air Act has not produced the desired results
B.
lead deposits in arctic snow are on the increase
C.
lead will stay in soil and snow longer than expected
D.
the US is the major source of lead pollution in arctic snow