The _________ on his face was kind of strange, when I told him the news. 

Professor Li, do you like Ewa and can you make a(n)_______ on her new movie?

As the quality of the city’s air continues to give rise to ______, the residents are encouraged to set off fewer fireworks.

Because of the continuous bad weather, the building work of the bridge over the Yangtze River is far behind        

Most air pollution is caused by the burning of ____ like coal, gas and oil.