IgG、IgM的补体结合点依次分别为()
A．CH2、CH3
B．CH1、CH2
C．CH1、CH3
D．VH、CH
E．VL、CH
参考答案：A
Is that his pen __________ the lost and found case?[ ]
A. at
B. on
C. in
D. by
犁煤器定位轴与导套应伸缩灵活，无晃动。当晃动超过0.1mm时，应更换导套。（）
