Unforgettable sight in Beijing

My friend saw an unforgettable sight during his recent visit to Beijing - something that he has not seen before, and will never see again in the future.

He looked up and saw a blue sky. In preparation for the Beijing Olympics which will start soon, the authority has asked the factories to stop or reduce their production within a large part of Beijing. This reduces the pollution and makes the air clean.

He expects that, after the Olympics, things will get back to normal in Beijing - and that is a polluted environment.