The stronger the ___________ is, the more quickly a person will learn a foreign language. That is to say, it is up to whether he has an interest in the foreign language. 

--What did he say in_______ of his stupid behavior?--He admitted having made a serious mistake.

Their products enjoy 30 percent ________ of the market in this country because both the quality and their service are fine. 

The World Health Organization gave a warning to the public without any ______when the virus of H1N1 hit Mexico in April, 2009. 

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