科学家表示，如果不采取措施减少密西西比河的含氮量，未来几年死水区会愈发扩大。

And scientists say it will grow larger in years to come, if something is not done to reduce the amount of nitrogen in the Mississippi River.

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科学家表示，如果不采取措施减少密西西比河的含氮量，未来几年死水区会愈发扩大。

And scientists say it will grow larger in years to come, if something is not done to reduce the amount of nitrogen in the Mississippi River.

youdao