产AmpC酶的肠杆菌科细菌感染，治疗可选用的抗生素是（）

A.一代头孢

B.二代头孢

C.三代头孢

D.四代头孢

E.碳青酶烯类

Aboard a vessel, dividing the sum of the vertical moment by the total weight yields the vessel’s（）.

A.vertical moment

B.transverse position of the center of gravity

C.inclining moment

D.righting moment