And that in turn leads to additional emissions of harmful pollutants and our area is very concerned about improving air quality as one of the key ways to make our communities even better places to live and work."

VOA: standard.2010.07.26

This led people to go back and look at the places that were manufacturing the vaccine to make sure that they were all producing vaccine of the proper quality.

这现象让人们回溯并且审视,制作疫苗的地方,以确认他们生产的疫苗,质量都合格

耶鲁公开课 - 生物医学工程探索课程节选