【正文】
g very quickly. You can see more museums, parks an shopping centers here and there. More and more highways and overhead walkways have been built up. What’s more, a lot more buses which burn cleaner fuel, such as CNG or LPG, are put into use, to prevent air from being polluted. Water in the rivers is clean again. Wherever you go, you can see green trees, grass and beautiful flowers. All these make life in Beijing more convenient, pleasant and colorful. Beijing is still advancing to the bright future. 北京有3000多年的歷史