The phenomenon of flutter occurs: A: Rather at low speed and low altitude. B: Rather at high altitude and high angle of attack. C: Rather at high speed. D: Rather transonic, beyond the critical Mach.

From a high angle overlooking the road, we watched the two cars racing toward one another, headed _________ a collision course.

What is the angle of repose? A: The angle of an inclined rock layer measured from a horizontal line B: The angle of the slip plane from a slide C: The angle of plunge into the interior D: The steepest angle at which a material remains at rest

The sum of rake Angle, clearance angle and wedge Angle is ( ).The sum of the major cutting edge angle, minor cutting edge angle, and tool included angle. is ( ) A: 90 ° , 180 ° B: 90 ° , 90 ° C: 180 ° , 180 ° D: 180 ° , 90 °

Using a right-hand hob with the lead angle ω cuts a left-hand gear with the helix angle β , hob swivel-setting angle δ is: A: ω B: β C: β-ω D: β+ω

按Angle 分类法以下何为正确 A: AngleⅠ类是正常咬合 B: AngleⅡ类多为反合 C: AngleⅢ类多为深覆盖 D: Angle Ⅲ 类的下颌为远中咬合关系 E: 右侧为AngleⅢ类关系,左侧为Ⅰ类关系时也属Angle Ⅲ 类错合

The transmission angle is always numerically equal to the angle between the coupler and rocker.

Measured<br/>in main section, the angle between the rake surface and the reference<br/>plane is (). A: rake γo B: clearance angle αo C: Cutting edge angle κr D: Inclination angle λs

按Angle分类法以下何为正确 A: Angle I类是正常咬合 B: Angle Ⅱ类多为反牙合 C: Angle Ⅲ类多为深覆盖 D: Angle Ⅲ类的下颌为远中咬合关系 E: 右侧为Angle Ⅲ类关系，左侧为I类关系时也属Angle Ⅲ类错牙合

The squatting posture will make the lower part of the screen appear heavier and the upper body slightly thinner, so _________ can be used. A: Side shot B: high angle shot C: Front shot D: Oblique side shooting