The United States National Aeronautics and space administration a research satellite launched in 1991, running for 3 years to study atmospheric ozone level mission.

美国航空航天局1991年发射这颗研究卫星，执行为期3年研究大气臭氧水平的使命。

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So it is with the National Aeronautics and Space Administration, the United States Geological Survey, the Environmental Protection Agency, and the Nuclear Regulatory Commission (NRC).

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