It offers a layer-development mode with the direction of the circle-and-layer theory in geography.

以地理学中的圈层理论为指导，提出了旅游资源的层次性开发模式；

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It offers a layer-development mode with the direction of the circle-and-layer theory in geography.

以地理学中的圈层理论为指导，提出了旅游资源的层次性开发模式；

youdao