A、 Mach digit is the percent of true airspeed to the speed of sound.
B、 Mach number is the ratio of true airspeed to the speed of sound.
C、 Mach number is the proportion of real airspeed to the speed of light.
答案：B
A、 Mach digit is the percent of true airspeed to the speed of sound.
B、 Mach number is the ratio of true airspeed to the speed of sound.
C、 Mach number is the proportion of real airspeed to the speed of light.
答案：B
A. You have the right to duplicate or publish this document or any substituent alteration or revision thereof, in whole or in part, free of charge.
B. You have the right to reproduce or publish this document or any subsequent modification or revision thereof, in whole or in part, free of charge.
C. You have the right to recopy or publish this document or any substantial alternation or revision thereof, in whole or in part, free of charge.
A. The applicant for an avoidance permit must show that the approval of the avoidance permit will not affect safety and must provide an explanation. The applicant shall take measures to ensure that the level of safety is equal to the level of safety provided
B. The petitioner for an exemption must include reasons why safety would not be adversely affected if the exemption is granted, or must explain the action to be taken by the petitioner to provide a level of safety equal to that provided by the rule from whic
C. The applicant for an exemption permit must state the reasons why safety will not be affected by the granted approval, or must take measures to ensure that the level of safety provided is consistent with the requirements of the regulations seeking exemptio
A. 重心是飞机悬浮时保持平衡的点。它与参考基准的距离是通过总力矩除以飞机的总重量得出的。
B. 飞机的重心是使飞机保持平衡的点。它与参考基准的距离可以通过总弯矩除以飞机总重量找到。
C. 重心是如果飞机悬着使飞机保持平衡的点。它到参照基准的距离可以通过总长度除以总重量找到。
A. 给轮胎放气。
B. 给轮胎充气。
C. 给机轮充气。
A. 描述飞机起落架时，应描述前轮制动。
B. 描述飞机起落架时，应描述机轮刹车。
C. 描述飞机起落架时，应描述机轮停车。
A. 确保杆之间有合适的间隙。
B. 确保杆之间有合适的角度。
C. 确保杆之间有足够的间隙。
A. 计划性勤务包括内部清理等工作。不包括维修工作实施所要求的润滑程序。
B. 计划性勤务包括内部清理等工作。不包括润滑程序，这是维修工作实施所要求的。
C. 计划性勤务包括内部整理等工作。不包括润滑程序，这是维修工作实施所要求的。
A. 扭矩测量仪是一个显示螺旋桨传动轴可用输出扭矩的指示系统。
B. 扭矩计可以显示传动轴的输出扭矩。
C. 指示系统必须显示扭矩计传动轴的可用输出扭矩。
A. 子段落和其从属信息，如图表列表，会显示在本部分的内容清单中。
B. 在本部分的目录中会展示次段落的相应信息，譬如数据列表。
C. 分段和其它相关信息，例如图表清单，可在本节的目录中显示。
A. It is the responsibility of the operator to ensure that alternative tools or equipment can work well and are dangerous to the parts and personnel as the ones specified in the procedure if you use them.
B. If alternative tools or equipment are used, the operator must ensure that they can play the same role and are as safe as the tools or equipment specified in the procedure to the parts and personnel.
C. If the manufacturer can make sure that alternative tools or equipment can meet the requirement and are as safe to the parts and equipment as the ones specified in the procedure, you can use them.
