happen, take place与occur用法辨析

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?你难道没想到就这事给他们打个电话?

事件作主语时,happen和occur可以通用?如:The accident happened/occurred yesterday. 事故是昨天发生的。

take place 指事件发生,但常用来表示“举行”的意思,带有非偶然性?例如:The meeting took place last night.会议昨晚举行。