人IgG各亚类活化补体的能力依次是() ["A．IgG1＞IgG2＞IgG3","B．IgG2＞IgG3＞IgG1","C．IgG3＞IgG1＞IgG2","D．IgG3＞IgG2＞IgG1","E．IgG2＞IgG1＞IgG3"]
避免引起铸件砂眼的具体措施有哪些?
IgG分子激活补体经典途径至少需要() ["A．一个IgG分子","B．二个IgG分子","C．三个IgG分子","D．四个IgG分子","E．五个IgG分子"]
惟一能通过胎盘的Ig是() ["A．IgG","B．IgA","C．IgM","D．IgD","E．IgE"]
能激活补体经典途经的Ig是() ["A．IgG1、IgG2、IgG3、IgM","B．IgG1、IgG2、IgG4、IgM","C．IgG、IgD、IgE、IgM","D．IgG4、IgA、IgE、IgD","E．凝聚的IgG4、IgD、IgE"]
铸件表面的缩孔是怎样形成的?
