1. 发生的事情；事件
    An occurrence is something that happens.

    e.g. Complaints seemed to be an everyday occurrence...
           似乎每天都有投诉。
    e.g. The food queues have become a daily occurrence across the country.
           排队购买食品的长龙已成了全国各地每日可见的景象。

2. 发生；出现
    The occurrence of something is the fact that it happens or is present.

occurrence什么意思

    e.g. The greatest occurrence of coronary heart disease is in those over 65.
           65岁以上者是冠心病的最高发人群。