Recently Peter________to do his homework, and instead insists on wasting his time playing com-puter games, which extremely annoys his father.

A．had been refusing

B．has been refusing

C．was refusing

D．refused

天疱疮病理特点为（）

A.棘层松解，上皮内疱

B.上皮下疱

C.上皮内水肿

D.上皮过度角化

E.上皮萎缩