Then over dinner,Franklin mentions that he 　　well since he gave up smoking and Dr Candy,the local doctor,offers to write him a prescription for some medicine.

A．had not been sleeping

B．has not been sleeping

C．is not sleeping

D．was not sleeping

细胞色素氧化酶含有的微量元素是（）。

A.钙

B.铁

C.锌

D.铜

E.硒