4．Beijing has been suffering this year's most severe smog since Friday，which has forced schools to close and traffic confusion．Thick，choking smog has enveloped the capital for five days，with the air quality index（指标）in many monitoring stations increasing to 500，the highest possible reading．The city government encourages people to stay indoors when the reading is higher than 300．
Concertration of PM 2.5-particulate matter with a diameter less than 2.5microns that causes health risks-was 689at 5pm on Tuesday in some sourthern Beijing monitoring stations，down from the peak reading of 945on Monday．
The capital has also seen more road accidents due to the poor visibility，and traffic jam was around the city through most of Monday．Many expressways linking Beijing and neighboring cities in Hebei province were closed for hours．
The city environmental watchdog sent inspection teams to supervise measures to limit emissions（排放）on Tuesday．Of 545companies they inspected，12had acted against orange alert restrictions，the capital's environmental protection bureau said．
For example，a Dongfeng Nissan factory to pause word on Tuesday．And a construction site at the China University of Political Science and Law left piles of building materials uncovered which could release dust in to the air．
All companies and construction sites against the regulations would be severely punished，the bureau said．
The smog covering a vast area across northern China has been caused by unfavorable weather，with no wind and high humidity，and an increased of coal in the heating season，the Ministry of Environmental Protection said．
29．We can infer from the first paragragh thatD
A．the smog is the most severe on Friday
B．people use envelopes in the capital
C．people stay at home doing some reading
D．the smog has taken place several times in Beijing this winter
30．How is paragragh 4and 5developed？A
A．Using examples and data B．Describing processes
C．Making comparisons D．Analyzing causes
31．Where dose this text probably come from？B
A．A sport magazine B．A newspaper report
C．A book review D．A museum guide．
分析 本文讲的是北京已经从星期五遭受今年最严重的烟雾，致使学校被迫关闭，交通混乱．首都的环境保护局采取了必要的措施来减轻烟雾．
解答 29．D．细节推断题．根据文中"Beijing has been suffering this year's most severe smog since Friday，"知这是最严重的一次，而不是唯一一次，所以可知是已经多次发生．故选D．
30．A．推理判断题．根据文中"For example，"知一定运用了举例，而又根据"Of 545companies they inspected，12had acted against orange alert restrictions，"知又运用了列数字的方法．故选A．
31．B．推理判断题．仔细阅读全文知这是一篇新闻报道．故选B．
点评 本文是新闻报道类阅读理解文章，阅读此类文章主要是要了解：
①新闻报道了什么事件；②事件是因为什么而发生的，相关背景如何；③文段中指出的事件发生过程中的突出细节是 什么；④事件造成的后果是什么；⑤事件的本质是什么，透过事件的表面现象，我们看到了什么社会问题．通过这样的梳理，我们就可以把新闻的脉络理清楚．这类材料命题点往往落在事实细节上
