A.少于100ml B.少于200ml C.少于300ml D.少于400ml
A.500ml B.1000ml C.1500ml D.2000ml
A.賁門括約肌發(fā)達 B.幽門括約肌發(fā)達 C.下食管括約肌壓力低 D.胃底發(fā)育差,呈水平