保证气动锚杆钻机的作业安全与最优运行，操作者使用前必须检查风源和水源，保证风压在（）以上，水压在0.6～1.2MPa。
A. 0.45MPa
B. 0.5MPa
C. 0.55MPa
D. 0.6MPa
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A sailing vessel is overtaking a power-driven vessel in a narrow channel，so as to pass on the power-driven vessel’s port side. The overtaken vessel will have to move to facilitate passage. The sailing vessel is the（）.
A. stand-on vessel and would sound two short blasts
B. give-way vessel and would sound no whistle signal
C. stand-on vessel and would sound no whistle signal
D. give-way vessel and would sound two prolonged blasts followed by two short blast
政治风险的类型有（）
A. 总体政局风险
B. 所有权/控制风险
C. 经营风险
D. 转移风险
在写作中，主要按做什么、怎么做的步骤来安排内容的文书是（）。
A. 计划
B. 讲述报告
C. 讲话稿
D. 总结
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