"Today,we've taken another step forward by - in leaving behind the legacy of the 20th century while building a more secure future for our children."

VOA: standard.2010.03.26

If a case of polio emerged in the community, the chances that it could spread to other children or to your child were high; so, great interest in this in the early part of this century.

如果在某个社区出现一例脊髓灰质炎患儿,那么你的孩子或者更多别的孩子,被传染的几率非常高,所以 二十世纪初的科学家们,热衷于研究脊髓灰质炎

耶鲁公开课 - 生物医学工程探索课程节选