有一种成分是补体反应的枢纽,既在两种激活途径中起中心作用,也是补体活化时正反馈的关键性成分的补体成分是()
A.C1
B.C2
C.C3
D.C4
E.C5
参考答案:A
The father as well as his three children ____ skating on the frozen river every Sunday afternoon in winter.
A.is going
B.go
C.goes
D.aregoing
下列不属于散粮船采取止移措施()
A.设置纵向隔壁
B.设置托盘
C.舱口盖固定装置
D.散谷表面上堆货