阅读理解。 Lights on thousands of miles of major roads in England could be dimmed (变暗) during quiet periods in a bid to save money and reduce carbon emissions from various vehicles. The Highways Agency suggests reducing light levels on A-roads when traffic levels Are' very low'.  I:ocal transport minister Norman Baker said he supported the. Move on condition. that safety was not compromised. Research into when and where lights could be dimmed will begin in May,2012. Mr.Kawczynski, a MP (国会议员), asked Transport Minister Norman  Baker 'what plans he has to change guidance on the, minimum amount of lighting required on A roads'.  In reply, Mr. Baker wrote:'The Highways Agency has plans to reduce the level of lighting on A-roads when traffic levels are far below road capacity.  The agency has no plans to reduce the level of lighting on A-roads during the peak (高峰) periods that occur during the hours of darkness or to temporarily switch A-roads lighting off when traffic flows  are  low. 'The  level  of  light. reduction will  be  based upon internationally agreed standards and made after discussion and  agreement with the UK's Institution of Lighting Professionals.' Mr. Baker added:'It is right that lighting authorities consider, in the interests of cost-saving and the environment, whether lighting can be sensibly dimmed or turned off . with proper safety brought into full consideration.' A Highways Agency spokesman said:'This is not about switching off lights on A- roads.  Any changes to light level will be determined after discussion and agreement with industry experts and will meet internationally agreed standards to ensure there will be no influence on safety for road users.' 1.  What is the text mainly about? A.  A bid for cost-saving and the environment by cutting light levels. B.  A research on when and where to reduce the light levels. C.  A discussion about changing the standard of lighting. D.  A move on the safety of A-roads. 2. Lights on major roads in England could be dimmed _____. A. in broad daylight. B.  during the peak periods C.  when traffic levels are very low D.  when there is power failure 3.   According to Mr. Baker, the level of light reduction will＿. A.  be determined after discussion and agreement with industry experts B.  be made only after discussion and agreement with the MP C.  surely have much influence on safety for road users D.  be based on internationaay agreed standards 4.   It can be inferred from the passage that A.  major roads in Britain may be less safer after reducing light levels B.  air pollution in Britain is becoming a big headache C.  Britain is suffering from heavy traffic D.  Britain is faced with a shortage of power