A:Marrying
B:Having married
C:Being married
D:Married
我国最早建立的高新技术产业开发实验区是____。
俄罗斯在世界上占有重要地位的产业是( )
已知两点A(1,2),B(3,1)到直线l的距离分别为2,5-2,则满足条件的直线l共有( )条