23. How did scientists discover the source of lead pollution in Greenland?
A) By analyzing the data published in journals like Nature and Ambio.
B) By observing the lead accumulations in different parts of the arctic area.
C) By studying the chemical elements of soil and snow in Northeastern America.
D) By comparing the chemical compositions of leaded gasoline used in various countries.(D)
24. The authors of the Ambio study have found that ________.
A) forests get rid of lead pollution faster than expected
B) lead accumulations in forests are more difficult to deal with
C) lead deposits are widely distributed in the forests of the US
D) the upper layers of soil in forests are easily polluted by lead emissions(A)
25. It can be inferred from the last paragraph that scientists ________.
A) are puzzled by the mystery of forest pollution
B) feel relieved by the use of unleaded gasoline
C) still consider lead pollution a problem
D) lack sufficient means to combat lead pollution(C)
A) By analyzing the data published in journals like Nature and Ambio.
B) By observing the lead accumulations in different parts of the arctic area.
C) By studying the chemical elements of soil and snow in Northeastern America.
D) By comparing the chemical compositions of leaded gasoline used in various countries.(D)
24. The authors of the Ambio study have found that ________.
A) forests get rid of lead pollution faster than expected
B) lead accumulations in forests are more difficult to deal with
C) lead deposits are widely distributed in the forests of the US
D) the upper layers of soil in forests are easily polluted by lead emissions(A)
25. It can be inferred from the last paragraph that scientists ________.
A) are puzzled by the mystery of forest pollution
B) feel relieved by the use of unleaded gasoline
C) still consider lead pollution a problem
D) lack sufficient means to combat lead pollution(C)