A.25~50ml/kg B.50~100ml/kg C.100~125ml/kg D.125~150ml/kg E.150~200ml/kg
A.5%~10% B.小于5% C.大于10% D.10%~15% E.15%~20%
A.腸道內感染 B.腸道外感染 C.血中IgM含量低 D.喂養(yǎng)不當 E.氣候突變