Another is that we learned a lot of things about engineering of public systems, like water supplies.

另一个原因是,我们懂得了有关公共系统知识,比如供水系统

耶鲁公开课 - 生物医学工程探索课程节选

You have to have a good public transportation system when you have as many people here as we do.

如果你那儿和我们这儿的人一样多，你们得有一个良好的公共交通系统。

纽约的交通手段 - SpeakingMax英语口语达人