病毒侵入机体后最早产生的有免疫调节作用的物质是()
A.SIgA
B.IFN
C.中和抗体
D.IgM
E.补体结合抗体
参考答案:B
In practice, it is usual for the ship to be loaded()to improve the vessel’s movement through the water.
A.a little deeper aft
B.a little deeper forward
C.at the same draught between fore and aft
D.a balance between two sides
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