In particular, dairy maids, whose responsibility was to milk cows, and so they had a very intimate relationship with cattle, often didn't get smallpox.

特别是挤奶女工，她们的职责就是挤奶，因此她们与牛有着非常亲密的关系，通常不会得天花。

youdao

Something like smallpox is hard to get, but there are other organisms that could become harmful.

像天花这种东西很难得到但是其他的有机体也可能会变得很危险。

youdao

And Jenner made the observation that others had made, that people that were around cows a lot tended not to get smallpox.

詹纳观察到的现象别人也曾观察到,就是经常接触奶牛的人不容易患天花

耶鲁公开课 - 生物医学工程探索课程节选

And he started with a similar but different observation, and that was that cows get a disease that's very similar to smallpox.

他首先观察到一种类似但不同的情况,就是牛得了一种很像天花的病

耶鲁公开课 - 生物医学工程探索课程节选

Then you start to get lesions on your skin that are very characteristic of smallpox.

然后你的皮肤就会遭到损害,这就是天花的典型特征

耶鲁公开课 - 生物医学工程探索课程节选

Yet keeping the smallpox around dramatically increases the risk that a deranged person will get his hands on it and release it in the population.

FORBES: It's time to destroy the U.S. smallpox reserves