【名词&注释】
医疗保健机构(institution of health care)、妊娠期妇女(pregnancy women)、避孕措施(contraception method)、遗传性疾病(hereditary diseases)、《婚姻法》(law of marriage)、多聚甲醛(paraformaldehyde)、牙髓失活剂(pulp devitalization)、明确规定(clearly stipulated)、婚姻法规定、结扎手术
[单选题]作为牙髓失活剂(pulp devitalization),多聚甲醛的含量一般是
A. 35%~60%
B. 20%~30%
C. 10%~20%
D. 5%~10%
E. 0.1%~0.5%