两个相邻的反向曲线间应保留一定的直线段长度，其半径应根据（）来确定。

A.曲线长

B.切线长

C.外距

— Are you________me of lying to the headmaster?

— I'm sure you did. [ ]

A. accusing  

B. scolding

C. reminding  

D. telling