BEIJING, March 19 (Xinhua) -- Beijing issued a blue alert for heavy air pollution Sunday morning.
The alert is forecast to last one day and people should take precautions and reduce outdoor activity, said a statement issued by the city's air pollution emergency response office.
At 10 a.m., readings at most of the city's monitoring stations for the hazardous fine particle matter PM2.5 exceeded 250 micrograms per cubic meter, according to Beijing Municipal Environmental Monitoring Center.
Air quality should improve Monday noon, the center said.
Beijing has a four-tier color alert system for pollution, with red being the highest, followed by orange, yellow and blue. The blue alert means the air quality index is forecast to reach between 200 and 300 PM2.5 for one day.
2014人教新目标英语八下unit 7《What’s the highest mountain in the world》section b 1c课本听力素材（mp3）
2014人教新目标英语八下unit 7《What’s the highest mountain in the world》section a 2a课本听力素材（mp3）
2014人教新目标英语八下unit 7《What’s the highest mountain in the world》 section a课件
2014人教新目标英语八下unit2《I’ll help to clean up the city parks》section a 2b课本听力素材（mp3）
2014人教新目标英语八下unit 7《What’s the highest mountain in the world》section a 3a课本听力素材（mp3）
2014人教新目标英语八下unit2《I’ll help to clean up the city parks》section a 1b课本听力素材（mp3）
2014人教新目标英语八下unit2《I’ll help to clean up the city parks》section b 2b课本听力素材（mp3）
2014人教新目标英语八下unit 7《What’s the highest mountain in the world》专题复习课件
2014人教新目标英语八下unit 8《Have you ever read treasure island yet》 period 1课件
2014人教新目标英语八下unit 9《Have you ever been to a museum》专题复习课件
2014人教新目标英语八下unit 6《An old man tried to move the mountains》课件3
2014人教新目标英语八下unit 6《An old man tried to move the mountains》课件4
2014人教新目标英语八下unit 7《What’s the highest mountain in the world》 section b课件
2014人教新目标英语八下unit 7《What’s the highest mountain in the world》section a 2d课本听力素材（mp3）
2014人教新目标英语八下unit2《I’ll help to clean up the city parks》section b 2a-2e课件
2014人教新目标英语八下unit 8《Have you ever read treasure island yet》 section a课件
2014人教新目标英语八下unit 7《What’s the highest mountain in the world》words单词听力朗读素材（mp3）
2014人教新目标英语八下unit 6《An old man tried to move the mountains》 words单词听力朗读素材（mp3）
2014人教新目标英语八下unit2《I’ll help to clean up the city parks》section a 2d课本听力素材（mp3）
2014人教新目标英语八年级下册unit 4《Why don’t you talk to your parents》section a 1a-2d课件
2014人教新目标英语八下unit2《I’ll help to clean up the city parks》section b 3a-3b（含self check）课件
2014人教新目标英语八下unit2《I’ll help to clean up the city parks》全单元课件
2014人教新目标英语八下unit 7《What’s the highest mountain in the world》课件
2014人教新目标英语八下unit 8《Have you ever read treasure island yet》section a 1b课本听力素材（mp3）
2014人教新目标英语八下unit 7《What’s the highest mountain in the world》section b 2b课本听力素材（mp3）
2014人教新目标英语八下unit 8《Have you ever read treasure island yet》section a 2a课本听力素材（mp3）
2014人教新目标英语八下unit 6《An old man tried to move the mountains》课件2
2014人教新目标英语八下unit 6《An old man tried to move the mountains》 section b 2b课本听力素材（mp3）
2014人教新目标英语八下unit2《I’ll help to clean up the city parks》section b 1a-1e课件
2014人教新目标英语八下unit2《I’ll help to clean up the city parks》section a 1a-2d课件