统计职业道德的核心内容是下列哪项（）。

A.忠于统计乐于奉献

B.实事求是不出假数

C.依法统计严守秘密

D.公正透明服务社会

From the ________ shown in the dead body, he ________to death by a certain poisonous chemical, but I can’t tell exactly which. [ ]

A. symptoms; must have been poisoned    

B. signs; should have been poisoned

C. symbols; could have been poisoned      

D. appearances; may have been poisoned