研究了0．005、0．05、0．10和0．15／mg／L四种不同浓度的Cd与0．10mg／LPb，0．05mg／LHg在日本鳗鱼肝脏、腮、鱼血和鱼肉的残留规律。分别将鳗鱼暴露于......

Acquired atresia of the external auditory canal(EAC)is a rare cause of conductive hearing loss.It has been traditionally......