happen有“偶然”的意思,多用于客观事物、情况的发生。如: Whatever has happened to your arm? It’s all swollen. 你的手臂怎么了?肿得好历害。 occur 指有计划地使某些事“发生”,有时强调“呈现”于人的知觉中。如: Did it occur to you to phone them about it? ...