自然通风系统中常见的通风筒有()
Ⅰ.烟斗式通风筒;
Ⅱ.排风筒;
Ⅲ.菌形通风筒;
Ⅳ.鹅颈式通风筒。
A.Ⅱ,Ⅲ,Ⅳ
B.Ⅰ,Ⅱ,Ⅲ
C.Ⅰ,Ⅲ,Ⅳ
D.Ⅰ~Ⅳ
参考答案:D
Of the following explanations, which is least likely to be a valid explanation for divergence between statistical significance and economic significance()
A. Transactions costs.
B. Data errors.
C. Taxes.
免疫比浊分析的影响因素有()
A.抗原抗体比例
B.抗体的质量
C.伪浊度
D.标准曲线制备与质量控制
E.以上都是