He helps his parents _____ the housework. [ ]

A. with

B. in

C. at

D. on

副溶血性弧菌对人类致病性叙述正确的是

A．主要引起食物中毒及急性胃肠炎

B．主要引起深部组织感染

C．主要引起脑膜炎

D．主要引起结节性坏死

E．主要引起肺部纤维化