Oil-gas resources are a base of upstream oil-gas industrial link and a guarantee of downstream industrial link as well.

油气资源是上游油气产业链的基础，是下游产业链的保障。

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Oil-gas resources are a base of upstream oil-gas industrial link and a guarantee of downstream industrial link as well.

油气资源是上游油气产业链的基础，是下游产业链的保障。

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