Ten years of efforts have seen continuous improvement in Beijing's air quality, and the city is confident it can make good on its promise for the Olympics.

The environmental authority say 70 percent of days this year in Beijing saw good air quality, up 40 percent from 1998.

Beijing has invested nearly 150 billion yuan in environmental protection since that time, and adopted various measures such as upgrading factory facilities, and raising the gas-emission standard.

(CCTV July 23, 2008)