incident 与 incidence

尽管名词 incident 与 incidence 的拼法与发音非常类似，但两者的意思却大为不同。[1] 以下，我将说明两个单词各自的正确用法。

incident：（令人不快的）事件。

1. In that incident, the level of contamination was between 6 and 16 ppm.
2. Most such incidents result in miscarriage.

incidence：（例如疾病的）发生或爆发；事件发生率。

3. The incidence of both of these diseases increased in the U.S. between 1994 and 2007.
4. The city has implemented measures to reduce the incidence of accidents at this intersection.

[1] 必须注意的是，除了此处讨论的意思之外，这两个单词都具有其他含义。