用低溶点合金浇注时，对零件浇注合金的部位必须用沙纸打磨，然后用丙酮或（）进行清洗，以去除铁锈、油污。
参考答案：甲苯
下列哪项不是皮质醇增多症患者的症状（）
A.糖尿病性的糖耐量异常
B.腹部和股部紫纹
C.向心性肥胖
D.骨质疏松，病理性骨折
E.低血钾
— She has gone abroad,______?
—No. She is still teaching us English at our school now.[ ]
A. is she
B. isn't she
C. has she
D. hasn't she
