【名词&注释】
过敏反应(allergic reaction)、解热镇痛药(antipyretic analgesics)、化学物质(chemicals)、多聚甲醛(paraformaldehyde)、安眠镇静药(soporific and sedative drugs)、行政主管部门(executive branch)、牙髓失活剂(pulp devitalization)、人民政府(s government)、磺胺类药(sulphonamide drug)、全社会参与(whole society commitment)
[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%