下面说法中错误的是[ ]
A．垂直于半径的直线与圆相切
B．切线垂直于过切点的半径
C．边数相同的正多边形都相似
D．正多边形是轴对称图形
答案：A
The result suggested that you ___. So I suggested that you ____ harder in the future. [ ]
A. fail; studied
B. failed; studied
C. failed; study
D. fail; study
类风湿关节炎病变进程中类风湿因子（IgG-RF）兼（）
A.抗原性
B.抗体性
C.感染性
D.遗传性
E.传染性
