A.2~8周 B.2~3个月 C.3~6个月 D.6~9个月 E.9个月以后
单项选择题儿童血清地高辛的有效血浓度为()
A.0~1ml B.2~4ng/ml C.1~3ng/ml D.1~4ng/ml E.0~3ng/ml