________ of the water in this cup ________ splashed onto the floor.[ ]

A. Three fourths; are

B. Three fourth; is

C. Three quarters; is

D. Three quarters; are

血浆游离Hb测定，下列何项是不正确的（）

A.需试剂，例如邻甲联苯胺

B.过氧化氢溶液要新鲜配制

C.比色波长620nm

D.与已知标准Hb液对照

E.采血和分离血浆过程中要严格防止体外溶血