Those who _____ in ____ compositions, please hand them in this afternoon.

A．hasn't handed; his

B．haven't handed; their

C．has handed; their

D．have handed; his

双抗体夹心法微粒子化学发光免疫分析中，将抗原-磁珠抗体复合物与非特异性物质快速分离的机制为（）

A.磁力的作用

B.电场力的作用

C.PEG的凝聚作用

D.洗涤

E.超速离心法