来自刘放军的问题
【MoreteensaresmokinginBeijing,______thenumberofprimaryandmiddleschoolstudentspickingupthehabithasmorethandoubledfrompreviousyears.A.whichB.whenC.whereD.that】
MoreteensaresmokinginBeijing,______thenumberofprimaryandmiddleschoolstudentspickingupthehabithasmorethandoubledfrompreviousyears.A.whichB.whenC.whereD.that

