正常血清中,补体含量最高的是
A. C1
B. C2
C3
D. C4
E. C5
当抗体与相应的抗原结合时,在以下何种情况下方能激活补体
A. CH1的补体结合点暴露
B. CH2的补体结合点暴露
CH3的补体结合点暴露
D. 借助抗原作桥梁
E. 直接同补体结合
经典途径激活血清补体作用最强的IgG是
A. IgG1
B. IgG2
C. IgG3
D. IgG4
E. IgM
When did Cooper meet with Tina?
A. at the autumn trade fair this year.
B. at the autumn trade fair last year.
C. at an exhibition last year.
D. at a cloth show.