.Some of his suggestions had been rejected _________ they were quite impracticable.

A．as

B．when

C．until

D．if

未经治疗时测得抗核抗体阳性率最高的疾病是（）

A.干燥综合征

B.慢性活动性肝炎

C.系统性红斑狼疮

D.硬皮病

E.类风湿关节炎