An "interbody fusion" is a bony bridge that "welds" the two vertebral bodies together to stop unstablemotion.
“椎体融合术”就是将两个脊椎连接起来防止脊椎不稳定的手术。
2
That is able to make the longitudinal motion of airplane unstable.
这足以使飞机纵向运动发生不稳定而危及安全。
3
When the motion of the basic state is the shear flow (or the differential rotation), this property means that the unstable waves would evolve automatically into the quasi-stationary stage.