There ______ quantities of apples in the basket and there was ______ milk in the bucket.

A．were; a number of

B．was; quantities of

C．were; a quantity of

D．was; a good many

刘某基于杀害潘某的意思将潘某勒昏，误以为其已死亡，为毁灭证据而将潘某扔下悬崖。事后查明，潘某不是被勒死而是从悬崖坠落致死。关于本案，下列哪些选项是正确的？（）

A.刘某在本案中存在因果关系的认识错误

B.刘某在本案中存在打击错误

C.刘某构成故意杀人罪未遂与过失致人死亡罪

D.刘某构成故意杀人罪既遂