Beijing Times reported the regulation, , would take effect on Jan．1, 2012．
A. if passing
B. if passed
C. if it passed
D. if it being passed
网友回答
A. if passing
(答案→)B. if passed
C. if it passed
D. if it being passed
解析：考查省略结构。if passed = if it was passed，如果被通过，选B。