【名词&注释】
免疫原性(immunogenicity)、免疫学(immunology)、物理性质(physical properties)、化学性质(chemical properties)、密切相关(closely related)、发生变化
[单选题]血液的比密(比重)正常参考范围是
A. 1.020~1.030 B. 1.030~1.040 C. 1.040~1.050 D. 1.050~1.060 E. 1.010~1.020