Images: Above Ice core close-up. American Museum of Natural History Below Inside the U.S. Geological Survey National Ice core Lab.

图片：上图冰芯特写美国自然历史博物馆；下图美国地质调查局冰芯实验室内部美国地质调查局。

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Thee survey, part of the American medical Association's Guidelines for Adolescent Preventive Services program, also includes questions about medical history, health, school, safety and substance use.

这项调查是美国医学联合会青少年预防服务项目的一部分，其涉及的问题还有医学历史、健康、学校、安全以及物质使用等。

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