早期胎传梅毒特有的临床表现是()
A.面部脂溢性皮炎
B.口角放射状皲裂及瘢痕
C.桑葚齿
D.马鞍鼻
E.玫瑰疹
参考答案:B
His father is _____ English teacher. [ ]
A. a
B. an
C. /
油罐检修洗刷后,封罐时做哪些工作?