骨巨细胞瘤Ⅱ级属于（）
A.良性骨肿瘤
B.恶性骨肿瘤
C.肿瘤样病变
D.继发性骨肿瘤
E.潜在恶性骨肿瘤
参考答案：E
The workmen made so much___________ that Mrs. Walker had to spend three days cleaning
up afterwards. [ ]
A. trouble
B. damage
C. mess
D. nuisance
清除不锈钢的腐蚀产物，不能用（）。
A、钢丝刷
B、砂纸
C、钢丝棉
D、喷丸方法
