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_______ the environmental protection project, the local river would have remained heavily polluted.

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Nuclear, wind, and solar power are _______ energy sources.

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In this zoo, some scientists are trying to _______ some species that are seriously endangered.

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_______ action earlier, the damage to coastal ecosystems would have been much less severe.

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If factories _______ proper filters, they wouldn’t have released so many harmful gases into the air.

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_______ people are choosing to support environmental charities through fundraising events.

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The less smoke is released into the air, the _______ the atmosphere becomes.

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The more we ignore climate change, _______ serious its impacts on the environment will be.