A.2x-y-1=0
B.2x+y+1=0
C.2x+y-3=0
D.2x-y-+3=0
[单选题]A.2x-y-1=0B.2x+y+1=0C.2x+y-3=0D.2x-y-+3=0
[问答题]=------------.
[问答题]
[单选题]( ).A.B.C.D.