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Many of the world’s big lakes are threatened by pollution or huge drainage schemes. But there is least one fairly bright spot. The Great Lakes and St. Lawrence river system between Canada and the United States, which together account for a fifth of the world’s non-polar fresh water, are much healthier than they were. Can they stay that way
Though Lake Michigan is wholly the United States, all five lakes are governed by the Boundary Waters Treaty of 1909, implemented by an independent bi-national joint commission. In 1978, both countries agreed to try to clean up the water in the lakes, several of which were heavily polluted. They have done so though in fact the improvement owes as much to economic change as to government action. Steel and other heavy industry have given way to cleaner industries and services, both in Ontario and in American lakeside states. The result: tests on fish and birds show residues of heavy metals have declined (t
A. Fish and birds show residues of heavy metal.
B. Toronto has grown salmon successfully in its waters.
C. Farming has prospered in the lakeside areas.
D. Lake water has been drawn for use by the population.
Text 1
Many of the world’s big lakes are threatened by pollution or huge drainage schemes. But there is least one fairly bright spot. The Great Lakes and St. Lawrence river system between Canada and the United States, which together account for a fifth of the world’s non-polar fresh water, are much healthier than they were. Can they stay that way
Though Lake Michigan is wholly the United States, all five lakes are governed by the Boundary Waters Treaty of 1909, implemented by an independent bi-national joint commission. In 1978, both countries agreed to try to clean up the water in the lakes, several of which were heavily polluted. They have done so though in fact the improvement owes as much to economic change as to government action. Steel and other heavy industry have given way to cleaner industries and services, both in Ontario and in American lakeside states. The result: tests on fish and birds show residues of heavy metals have declined (t
A. Fish farming.
B. Urban population.
C. Decreased rainfall.
D. More landslide.
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