A.变长
B.变短
C.保持不变
D.不能确定
[单选题]A.y-x=1B.y-x=2C.y+x=1D.y+x=2E.2y-3x=1
[单选题]A.B.C.D.E.
[单选题]A.B.C.D.
[单选题]A.变长B.变短C.保持不变D.不能确定
[单选题]A.7.0B.26C.53D.0.26