上反角使飞机具有横侧安定性的原因是（）.A.侧滑时，上反角使侧滑一侧机翼的迎角减小，

When developing the project charter, any kind of the organzation's enterprise environmental factors must be considered. This may include the following EXCEPT______.

A．company reputation

B．personnel administration procedure, including training records

C．existing facilities and capital equipment

D．stakeholder risk tolerances

曾因过失犯罪受过刑事处罚的，可以担任人民警察。( )

用齿厚游标卡尺测量分度圆直径d₁为50mm，轴向模数m_x为5mm的双头米制蜗杆的法向齿厚s_n，问齿高卡尺应调整到什么尺寸法向齿厚的基本尺寸应为多少

燃烧煤气窑炉，送煤气不着火或点着火后又熄灭应如何处理？