early 15c., "incidental matter," from Middle French incidence (15c.), from Late Latin incidentia (see incident (n.)). Meaning "act of coming into contact with" is from 1650s; sense in physics is from 1620s.
权威例句
1. an area with a high incidence of crime
犯罪率高的地区
2. This area has a high incidence of crime, disease, unemployment, etc.
这个地区的犯罪率 、 发病率 、 失业率等很高.
3. The report analyses the incidence of cancer among people aged 0 - 24.
这份报告分析了从0 岁 到24岁的人的癌症发病率.
4. The change in smoking is paralleled by a change in the incidence of lung cancer.
吸烟情况的变化与肺癌发病率的变化如影随形。
5. It was noted that within a year the incidence of illness had increased quite significantly.