(1)发生(take place;come into being;happen)[I]：Many accidents～in the home.许多意外事故是在家里发生的。Several murders～during the last act of the play.在戏的最后一幕中发生了好几起谋杀事件。When did the earthquake～? 地震是什么时候发生的?〖同〗happen，befall，result;

(2)存在，出现，被发现(exist;appear;be found)[I，I+prep](fml)：Misprints～on every page.每页上都有印刷错误。Oil～s under the North Sea.北海下面发现了石油。Tuberculosis～s most often in damp climates.结核病多见于气候潮湿地区。〖同〗appear，arise，rise，emerge;〖反〗disappear，vanish;

(3)想到(起)(come into one's mind)[I+prep(to)]：An idea～red to him.他想起了一个主意。It～red to me to visit my parents.我想到了去看望父母。Did it ever～to you that she needs you? 你曾想到过她需要你吗?

→oc′currence n;

【辨异】occur与happen和chance的区别见CHANCE。