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

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Many endangered species will keep losing their _______ unless we reduce deforestation.

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_______ we continue to protest against overfishing, the government could pass more laws to ban it.

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The huge crowd is _______ about the local water pollution, showing lots of signs and banners on the streets.

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Some species might go extinct _______ we reduce deforestation.

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

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

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Using _______ products which are not harmful to the environment is now becoming more and more popular.