An orange alert means heavy pollution — PM2.5 higher than 150 — for three consecutive days.

橙色预警意味着连续三天的重污染，PM 2.5指数高于150。

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China's central meteorological administration has continued its orange alert for the typhoon.

中国中央气象局继续发布台风橙色警报。

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An even larger region is under orange alert for smog, after red alerts late last month forced traffic off the roads and closed some schools.

启动霾橙色预警的地区范围更大。上月底发布的红色预警曾导致车辆限行和学校关闭。

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because all we konw now it's orange alert, the alert level has gone up or gone down We don't really know what it goes on behind the scene.

我们都知道现在是橙色警报，警戒线时高时低,我们真的不知道,事情背后是如何处理的。

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They said an orange alert was in effect for trains, buses and the airports.

NPR: New York, Los Angeles Step Up Security

New York City is to remain on Orange alert, and airspace restrictions for Washington and New York introduced during the war against Iraq will remain in place but under review.

CNN: Terror threat lowered to Yellow

New York has been on "orange" alert, or the second-highest level -- indicating a high risk of terror attack -- since the color-coded warning system was established after the September 11, 2001 attacks.

CNN: New York subway system on alert