[单项选择]Cars and other road vehicles are the single main source of harmful nitrogen oxides.
Road transport remains the biggest source of harmful air pollution in the EU despite efforts to reduce emissions over the past decades.
A report published by the European Environment Agency (EEA.) shows that it is the single main source of nitrogen oxides, carbon monoxide and non-methane volatile organic compounds.
It is also the second most important source of PM10 and PM2.5 particles.
As well as road transport, manufacturing industries, construction, the residential sector and agriculture are the main sources of air pollution in Europe today, the agency said.
The EEA said: "Particulate matter from sources such as vehicle exhausts and residential heating can affect the lungs and harm people of all ages, but it is known to pose an extra risk to those with existing heart and respiratory problems."
"Air pollutants are also responsible for the acidification of forests and wate
A. Air pollution.
B. Nitrogen oxide.
C. Road transport.
D. Organic compounds.