The health official said ________ 12 suspected cases of H1N1 were tested negative and ________，

so far, this city has reported no case of the virus.[ ]

A．what; that  

B．that; what

C．/; that  

D．that; /

下列关于基因表达的概念叙述正确的是（）

A.其产物总是蛋白质

B.其产物总是RNA

C.其产物可以是RNA或蛋白质

D.其产物不包括RNA

E.其产物不包括蛋白质