The wound is festering, and gangrene has set in.

伤口在化脓，继而发生了坏疽。

《柯林斯英汉双解大词典》

The spring-sowing time has set in.

春播季节到来了。

《新英汉大辞典》

Spring has set in.

春天来到了。

《新英汉大辞典》

His company NComputing says it has set up over forty thousand networks in more than one hundred countries.

VOA: special.2010.04.12

You might say, "Look, the physicalist can't tell us that, because all the physical parts are still there when you've got the corpse, at least if it's a fresh corpse before the decay has set in.

你可能会说,你看,物理主义不会告诉我们那些的,因为尸体所有的,身体器官部分都还存在,至少对于还未腐烂的尸体而言是这样的

耶鲁公开课 - 死亡课程节选

The sheer cacophony of the clustered consonants in this line sets off -or has the potential to set off -- a powerful cluster of feelings.

这句诗中辅音全然不和谐，使人觉得,或者有意向让人觉得-，有力量的层叠之感。

耶鲁公开课 - 弥尔顿课程节选

But while the precedent of abdication has set in the Netherlands, it hasn't yet taken hold elsewhere.

CNN: Will any of Europe's other older royals step down?

Based on fans' Twitter reaction, it's obvious that anxiety, or at the very least skepticism, has set in.

CNN: DC Comics goes for No. 1, fans conflicted

"Quite obviously, the confusion which has set in will only increase 'Sarkozy nostalgia', " says Jacques Camus in La Republique du Centre.

BBC: French papers unimpressed by UMP leadership "chaos"