What is it? [ ]
A. It is an apple.
B. It is red.
C. It is big.
答案：A
能抑制经典途径C3转化酶形成的因子有______、_______、______和______。
附壁血栓一般不会发生在
A．心房B．小静脉C．心瓣膜D．主动脉瘤
