Thank you for sending us ___________ fresh vegetables of many kinds. You have offered us __________ great service.

A．不填, a

B．the, 不填

C．不填, 不填

D．不填, the

I was so _________ as to believe everything he said. I now hate myself for being so simple-minded. [      ]

A. confident      

B. frequent    

C. intelligent    

D. innocent