Do you know ______ this time yesterday?

A．what he is cooking

B．what is she cooking

C．what he was cooking

D．what was she cooking.

某集中器现场抄读485总表数据失败，可能原因是（）。

A.载波表故障

B.部分载波表被拆除

C.现场表计清理不正确

D.集中器485抄表口故障。