Which one of the following sentences is correct?
A. There is too much pollution these days.
B. There are too many pollution these days.
Which of the following ways is not the best way to disagree with someone.
A. I'm not sure if I agree with you.
B. I don't really agree _______.
C. No.
诊断制剂的作用是( )传染源。
A. 预防
B. 诊断
C. 治疗
D. 中和
抗体主要存在血清中,故诊断抗体主要成分是( )。
A. IgG
B. IgA
C. IgD
D. IgE
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