The writer observes that survival is a difficult endeavor and that the world can sometimes seem harshly hostile.

作者发现，人类需要通过努力而生存,但这个世界往往是非常残酷的。

耶鲁公开课 - 旧约导论课程节选

Plus it makes it, as I talked about last time, much easier to think about distributing the vaccine around the world because shots require skilled medical personnel, whereas, an oral vaccine could be self-administered.

而且,这会使得,就像我上次谈到的,这会使得疫苗更容易在世界范围内分发,因为注射需要专业医疗人员,但是,口服疫苗自己就可以服用

耶鲁公开课 - 生物医学工程探索课程节选