air alert

Until the alert is lifted, Beijing's kindergartens, primary schools and private training schools are also Forecasters are suggesting the main reason for the heavy smog is a lack of air flow.

违反规定将面临重罚。在红色警报解除之前，北京的幼儿园、小学和私立培训学校也采取停课措施。气象预报显示造成雾霾的主要原因是缺乏气流。

Aircraft in the mideast are on air alert.

中东的飞机响起了空袭警报.

Worsening air quality in Beijing prompted authorities to activate the red alert around 4 pm on Friday, several hours ahead of the original plans.

…北京空气质量恶化促使当局在星期五下午4点左右启动红色警报，比原计划提前几个小时。

There were 15 minutes between the first air raid alert and the sounding of the all-clear signal.

第一次空袭警报和空袭警报解除信号之间间隔了15分钟。

Toxic smog blankets Shanghai. Last week, officials in Beijing issued an unprecedented red alert over air pollution.

有毒雾霾笼罩上海。上周，北京官员发出了史无前例的空气污染红色警报。