After ____ seemed like hours he came out with a bitter smile.

A．which 　

B．it

C．what　

D．that

下列疾病患者血清中抗核抗体的阳性率最高的是（）.

A.多发性骨髓瘤

B.系统性红斑狼疮

C.自身溶血性贫血

D.甲状腺肿大

E.萎缩性胃炎