Many methods, once developed, are kept purposely static so that data can be compared over long periods of time.

新方法一但确立，会有意保持其不变，以便数据长期具有可比性。

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The SAT is owned, published, and developed by the College Board, a non-profit organization in the United States, and was once developed, published, and scored by the Educational Testing Service (ETS).

SAT由美国一家非盈利组织-大学理事会拥有、出版和制定，曾经由美国教育考试服务中心(ets)开发、发行和评分。

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The SAT is owned, published, and developed by the College Board, a non-profit organization in the United States, and was once developed, published, and scored by the Educational Testing Service (ETS).

SAT由美国一家非盈利组织-大学理事会拥有、出版和制定，曾经由美国教育考试服务中心(ets)开发、发行和评分。

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