Conventional air pollution monitors are normally fixed on lampposts at about nine feet in the air.

传统的空气污染监测仪通常安装在灯柱上，并被固定在距离地面约九英尺的空中。

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There will be television chat shows hosted by robots, and cars with pollution monitors that will disable them when they offend.

届时，将出现由机器人主持的电视谈话节目以及装有污染监控器的汽车，一旦这些汽车排污超标（违规），监控器就会使其停驶。

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This is why many air pollution monitors have been set up, because public health authorities want to know if there is a need to issue an alert for bad pollution.

这就是为什么许多城市建立了空气污染监测，因为公共卫生当局想确定是否需要发布环境污染警报。

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Pollution monitors often collect particulates that measure 10 micrometres across, known as PM10s, as well as the smaller PM2.5s.

BBC: Railway tracks