What this does is it increases the role of this commercial middle class.

这点就增强了中产阶级,在商业中发挥的作用

耶鲁公开课 - 欧洲文明课程节选

It increases the role of cities, particularly port cities, which Amsterdam is.

同时也增强了城市的作用,特别是海港城市,例如阿姆斯特丹

耶鲁公开课 - 欧洲文明课程节选

You have to inject it multiple times because the first blip that you get in immune response is not very high, you have to boost and often you have to boost again in order to get a high enough response to be protected.

你必须得进行多次注射,因为第一次注射,无法使免疫系统产生强烈反应,你得要增强免疫,通常还得再增强一次,以使反应足够强烈,从而起到保护作用

耶鲁公开课 - 生物医学工程探索课程节选