So, if you want to attack urban air quality, this is probably moving in the wrong direction, OK?

所以如果你想攻击都市的空气质量，这可能是一个错误的方向，对吗？

麻省理工公开课 - 固态化学导论课程节选

If you're expecting to be attacked and besieged, as all these citadels would be by an invader, you would want more than anything else a water supply, but they didn't necessarily have good water supplies in such circumstances.

如果你预料到会被攻击和包围,就像这些城邦面对侵略者那样,你最关心的一定是水源供应,但在这样的情况下,他们未必能找到充足的水源

耶鲁公开课 - 古希腊历史简介课程节选