北京再發紅色預警 機動車單雙號限行

China warned residents across a large part of northern China on Friday to prepare for a wave of choking smog arriving over the weekend, the worst of which is expected to over capital Beijing, prompting the city to issue its second ever "red alert".

週五，中國向北方大部分居民發出預警，提醒他們要爲應對週末來臨的霧霾大潮做好準備。這是北京第二次發佈最嚴重的紅色預警信號。

The National Meteorological Centre said the smog would stretch from Xian, home to the Terracotta Warriors, across part of central China, through Beijing and up into Shenyang and Harbin in China's frigid northeast.

國家氣象中心報告，霧霾會從兵馬俑之都西安蔓延開來，穿過中部一些地區，到達北京；北至瀋陽和東北嚴寒之地哈爾濱。

The air pollution will begin rolling in from about Saturday evening and last until Tuesday, with visibility in the worst affected areas such as Beijing likely to fall to less than one kms (0.6 miles), it said.

氣象中心表示，空氣污染將從週六傍晚持續到下週四；在北京這樣的重災區，能見度會下降至一公里甚至更小。

In Beijing and parts of Hebei province, which surrounds the capital, the pollution index will probably exceed 500, it said. At levels higher than 300, residents are encouraged to remain indoors, according to government guidelines.

中心還報告，在北京和首都周邊的河北地區，污染指數可能會超過500。根據政府的指南，在污染指數超過300的情況下，居民不宜到戶外走動。

The Beijing city government issued its first "red alert" last week following criticism that previous bouts of smog had failed to trigger the highest warning level.

之前霧霾肆虐，北京市政府未發佈最高預警，由此招致諸多批評。上週，北京市政府終於發佈了首次紅色預警信號。

A red alert is triggered when the government believes air quality will surpass a level of 200 on an air quality index that measures various pollutants for at least three days. The U.S. government deems a level of more than 200 "very unhealthy".

當政府認爲空氣質量指數會在三日以上都超過200，就會發布紅色預警信號。美國政府認爲高於200的空氣質量指數是“非常不健康”的。

In Beijing, a red alert means around half the vehicles are removed from the roads with an odd-even license plate system enforced, schools are recommended to close and outdoor construction banned.

在北京，紅色預警信號表示政府將執行機動車單雙號限行，學校會被建議聽課，而戶外建築工地會被禁止作業。