In fact, subtle changes in program behaviour and timing can cause them to appear unexpectedly. Some examples are.

实际上，对程序行为和计时的细微更改可能导致这些异常的意外出现。

youdao

Other "cells" appear to assist me, extra resources fall into my lap unexpectedly, or I enjoy unusually good luck.

其他的“细胞”显得也正在帮助我，有额外的资源意外地落进我的怀抱，或者我享受到了不常有的好运气。

youdao

No one likes things to break. We don't like holes to appear in airplane cabins unexpectedly;

没人希望发生坏事.我们不会希望飞机的客舱内突然出现一个洞;

youdao

Polunin, who at 19 became the Royal Ballet's youngest male principal, shocked the dance world in January 2012 by unexpectedly quitting a week before he was due to appear as the lead in a production of The Dream.

BBC: Ballet star Sergei Polunin exits Midnight Express