A. male coupling at both ends B. female coupling at both ends C. female coupling at the nozzle end and a male coupling at the hydrant end D. male coupling at the nozzle end and a female coupling at the hydrant end
A. 没有什么原则 B. 整体性原则 C. 规范性原则 D. 有效性原则
A. SQL2005 B. ORCLE10g C. SQL2000 D. MySQL
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