A curve is a line no part is straight and which has no angle.
A. that
B. whose
C. of which
D. which
网友回答
A. that
B. whose
(答案→)C. of which
D. which
解析：考查定语从句。在定语从句中，that作主语或宾语，whose作定语，后跟名词或代词；which作主语或宾语，of which相当于whose，常构成of which+the+名词或the+名词+of which结构，因为part前有no，所以不能直接用whose，故选C。