钢筋弯曲机作业中,严禁()。
A.更换轴芯、销子
B.不变换角度
C.调速
D.清扫
E.加油
参考答案:A, C, D, E
______ I have made great progress in my spoken English, I can not express myself freely.
A.In spite of
B.Even though
C.As though
D.Despite
食管化学灼伤()
A.黏膜呈串珠样改变
B.黏膜破坏,中断
C.出现鸟嘴状狭窄,黏膜光滑
D.黏膜不规整,细线状狭窄
E.黏膜光滑完整