The manager listened to the customers’ complaints attentively with great patience, _______ to miss any point.

A．not trying

B．trying not

C．to try not

D．not to try

引起鹅口疮的病原菌是（）

A.艰难梭菌

B.大肠埃希菌

C.白假丝酵母菌

D.变异链球菌

E.甲型溶血性链球菌