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下列命题是真命题的是( ) A.对角线相等且互相垂直的四边形是菱形 B.平移不改...
下列命题是真命题的是( )
A.对角线相等且互相垂直的四边形是菱形
B.平移不改变图形的形状和大小
C.对角线互相垂直的梯形是等腰梯形
D.相等的弦所对的弧相等
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