Tom’s __towards guests really makes me feel embarrassed in the party. 

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

Urban (城市) crowdedness would be greatly relieved if only the_______ charged on public transport were more reasonable.

This is a new ______ to language teaching, which can stimulate students’ interest to learn the language.

Festivals are a great time for people to meet friends and enjoy each other’s _____.