Asia-Pacific Economic Cooperation(APEC) members met in Beijing from November 5 to 11 to discuss the future of APEC and the overall development of the Asia-Pacific area. APEC, which was set up  in 1989,is a forum  for 21  member countries to develop free trade and economic cooperation throughout the Asia-Pacific area. Though Asia-Pacific Economic Cooperation came to a successful close, the "APEC Blue" has become popular in Beijing, even in China. A clear blue sky in Beijing is difficult to see during the smog  season, so Beijingers gave it a name: "APEC Blue". "Oh, how beautiful the autumn sky is and how fresh the air is!" This is how most Beijingers feel during APEC. "I hope the APEC Blue will remain, and I believe, through the efforts we continue to make, it will." A lot of environmentally friendly ways were taken to reduce  the Beijing smog during the APEC meeting, including limiting the number of cars on the road, stopping some factories in neighboring cities and so on. Perhaps we can learn something from London, where the Great Smog killed 4,000 people :in four days in 1952. Britain then passed its first air pollution act, which required that all power plants in London should be shut down, factories must build taller chimneys, and the heating system must be improved. In order to keep "APEC Blue", Beijing plans to build air corridors  to blow away pollution. Not all agree with this way. Song Guojun, a professor  of _  at Renmin University, believes that this way will not solve the problem at its root, and only by controlling the source  of pollution will Beijing see bluer skies. According to the passage,  _  is not right.
Beijingers believe the APEC blue will remain, if they continue making efforts. A lot of ways were taken to reduce the Beijing smog. The Great Smog killed 4,000 people :in four days in 1952 in London. Song Guojun believes that no way will solve the problem at its root.