重症急性胰腺炎最常见的并发症是（）

A.化脓性腹膜炎

B.脓毒血症

C.消化道出血

D.胰周脓肿

E.休克

We ____ here two hours ago . We ____ here for two hours .        [ ]

A. have arrived, have been      

B. have come, have been

C. came, have come            

D. arrived, have been