根据短文内容及首字母提示，填写所缺单词，使短文意思完整（每空一词）
Sweeping city skies
We always check the weather before a trip. But after hearing a lot about air pollution .we often wonder:  h_____ will the air be tomorrow?
On Sept 1, forecasting air pollution  started to be on TV. There are six grades, with the first grade  meaningexcellent air.
The forecast helps us  plan trips, and helps the government make plans to stop air p______. China is t_____ its best to clean the air.
Big cities such as Beijing and Shanghai are taking the air pollution   seriously first.
On Sept 2, Beijing said it will reducePM2.5 density (密度) by at l____25 percent by 2017.
How will the city make it come t_______?
Car emissions (排放物) is one of the main  r_______ of PM2.5 in big cities. So fewer cars will be in Beijing next year. It is also  asking for congestion fees (拥堵费) from car driving in the city center.
There’s a lot of PM2.5 in waste gas（废气）from factories. Beijing will close some companies . If a company pollutes h_____, it will have to buy water and electricity at a  h______price.
In order to have more blue  s______ , every one of us should also help.
We can help by taking buses i______ of cars or taxies. We can also help by giving up smoking.
So from now on, take action and do your part.