ladder effect

... ladder drilling ==> 梯架式钻孔,梯式钻眼法 ladder effect ==> 梯形效应 ladder escape ==> 安全梯 ...

 trapezium effect

... trapezium distortion 梯形失真 trapezium effect 梯形效应 trapezium modulation 梯形调制 ...

 keystone effect

... keystone distortion 梯形畸变; 梯形失真 keystone effect 梯形效应 keystone fault 拱楔断层; 穹顶断层 ...