多发性肌炎首选治疗为（）
A.皮质类固醇
B.免疫抑制剂
C.血浆置换
D.免疫球蛋白
E.高蛋白饮食
参考答案：A
______ it is very late, ______ my mother is still at work. [ ]
A. Although; but
B. Although; and
C. Although; /
D. Although; or
交接箱地线的接地电阻应小于（）
A.6欧姆
B.8欧姆
C.10欧姆
D.12欧姆
