Vandalism used to be a rare occurrence here.

过去这里很少发生故意破坏公物的事。

Whales and dolphins have been found with hind limbs; this rare occurrence is due to the reemergence of a trait they inherited from their terrestrial ancestors.

发现鲸和海豚身上有后肢；这种稀有的现象是由于它们在陆地上的祖先身上的特征再次被遗传。

Laughter was a rare occurrence in his classroom.

他的课堂上难得有笑声。

Fixed unable to drag capsized Rafts on rare occurrence.

固定无法拖动倾覆筏在罕见的发生。

This is rare occurrence as our climate seldom goes to extremes.

在我们这里，这种事情很少见，因为气候很少发生异常。