Translation 2 (English-->Chinese) Part 1

This was from an exam to test us on vocabulary, hence why I don't know some phrases or expressions. I did this without a dictionary.

English: China pollution: First ever red alert in effect in Beijing

Schools in Beijing are closed and outdoor construction halted as the Chinese capital's first ever pollution "red alert" came into effect. Limits have been placed on car use and some factories have been ordered to stop operations. Cars are only permitted to drive on alternate days, depending on whether a car's number plate ends in an odd or even number.
It is the first time Beijing has declared a red alert, although pollution levels were far from the city's worst.
According to the US Embassy, its air pollution monitor in Beijing reported that the intensity of PM 2.5 was at 291 micrograms (微克) per cubic metre (立方米)- a level it described as "very unhealthy".

中文：中国的空气污染：北京第一个红警告生效了（北京首次红色预警启动）。

因为中国的首都第一个污染红警告生效了，所以北京的学校都关门了而且外边的建设都停止了（伴随着首都北京第一次红色预警的启动，北京的学校和户外施工都关闭停止了）。使用汽车被控制（汽车被限制使用）而且一些工厂被令停止操作。汽车只允许没两天开车（每两天出行一次）并且（基于）那就看是否它们的最后的号码是________或______（他们车牌号码最后一位的单双号）。

这是北京第一次发布一个“红（色)警告”，尽管空气污染的水平仍然不是城市最不良的(远不及城市最低水平）。
根据美国大使馆来看，在北京的空气污染的检验机报道PM2.5的深化（强度）是每个立方米291微克 - 一个“非常不健康”的水平。