Do you remember ______? [ ]

A. where did you buy the dictionary

B. where you bought the dictionary

C. where do you buy the dictionary

D. where you buy the dictionary

氟尿嘧啶的抗癌作用机理是：

A．阻碍DNA合成
B．与DNA联结而破坏其结构
C．与DNA结合而阻碍RNA转录
D．阻碍纺锤丝形成
E．阻碍蛋白质合成