There is always an unstable region or break in the static pressure curve of a propeller fan .

在螺旋桨式风机的静压曲线中存在着不稳定区域或断点。

The unstable region shows the potential of the economic downturn to inflame simmering tensions.

该地区动荡不安表明,经济低迷可能会引爆蓄势已久的紧张局势.

For in our unstable region, no one can guarantee that our peace partners today will be there tomorrow.

在我们的不稳定地区，没有人能够保证我们今天的和平伙伴明天还是和平的。