NASA's George Diller said the station is easily visible from Earth because it is more than "It is a large object, getting bigger all the time."

VOA: standard.2010.04.05

Or vaccines that could be transported more easily— the hepatitis vaccine that we get is not stable unless it's refrigerated.

或者令疫苗更易于运输,现在的肝炎疫苗一定要冷藏,否则它就不稳定

耶鲁公开课 - 生物医学工程探索课程节选