单选题 To maintain public______is not only the policemen's duty but also every citizen's responsibility.
A. custom B. confidence C. security D. simplicity

【正确答案】 C

【答案解析】[解析] 本题空格处是说维护公共安全。C项“security安全”符合题意。其他三项 “custom风俗；confidence信心；simplicity简单，朴素”都不正确。