Traffic restrictions have come into effect in Beijing to improve the capital’s air quality

Traffic restrictions have come into effect in Beijing to improve the capital’s air quality and traffic situation for the 2008 Olympics．
A. in order that
B. in an attempt
C. at an attempt
D. in a try

A. in order that(答案→)B. in an attemptC. at an attemptD. in a try解析：in an attempt to do sth努力尝试做某事。

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