Traffic restrictions have e 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
网友回答
A. in order that
(答案→)B. in an attempt
C. at an attempt
D. in a try
解析：in an attempt to do sth努力尝试做某事。