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Tracy: “I think plastic bags are not as harmful as people say. Instead, they provide great convenience.”

Nathan: “______. Plastic bags are among the biggest threats to our environment.”

What does the notice mean?

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The national park was established to ______ the ecosystem of the limestone forests.

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Some people ______ down lots of trees along the river for the past two weeks.

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The red squirrel in England is in danger of ______.

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Natural resource managers ______ the needs and behaviors of wildlife.

Find the mistake.

The local farmers are trying to stop the invasive species from spreading for the past six months.

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Naturally, many different species in this freshwater ecosystem share the same kind of ______.