Every once in awhile, the rangers must crack down on reckless pilots of air boats that skim across the swamp, endangering themselves and others and tearing up delicate foliage.

VOA: standard.2010.03.29

And at particular points,when there is something important about the different translations, I'll bring that up,and I'll explain every once in awhile.

某些时候，不同译本中,有什么重要地方需要指出时，我会告诉大家并给出解释。

耶鲁公开课 - 新约课程节选

But once in awhile, one of these plus twos comes in almost on axis, and it gets whipped around by the Coulombic repulsive forces.

但是偶尔一个带两个正电荷的粒子,以接近于轴的位置进入，会快速的移动到周围,由于库仑斥力的作用。

麻省理工公开课 - 固态化学导论课程节选

The Okefenokee,which is already nearly choked with plants, would probably fill in,dry up, and become just another cypress and pine forest were it not for range fires that come along every once in awhile and burn out decayed vegetation.

VOA: standard.2010.03.29

There we go. Now if I do this, an infinite number of times, we should get roughly 50/50, but now we have the ability to do things only once in awhile.

开始，如果我们，不停地按这个按钮，我们大致会有一半的机会听到猫叫，但是我们每次只有一次按按钮的机会。

哈佛公开课 - 计算机科学课程节选