下列哪些人员不能凭相关有效证件免费乘坐地铁（）。
A.义务兵
B.革命伤残军人
C.公安
D.伤残人民警察
参考答案：C
高山族主要分布在那个省级行政区？[ ]
A．台湾省
B．云南省
C．北京市
D．西藏自治区
_____ his writing, the writer forgot to have his lunch. [ ]
A. Was absorbed in
B. Absorbed in
C. Absorbed into
D. Was absorbed into
