Before specific solutions can be tested, NASA must first collect data on how the rotor blades interact with air under a variety of operating conditions.
在测试特定的方案以前,NASA必须首先搜集在不同的运行条件下桨叶与空气如何相互作用的数据。
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Researchers at the University of Colorado tested 45 showers in five states as part of a larger study of the microbiology of air and water in homes, schools and public buildings.