illness和sickness可數(shù)嗎

　　例句：

　　In fifty-two years of working he had one week of sickness.

　　他在52年的工作時間里曾生過1星期的病。

　　We strongly recommend insuring against sickness or injury.

　　我們強(qiáng)烈建議投傷病保險。

　　I recommend you get insurance against sickness and unemployment.

　　我建議你辦個疾病和失業(yè)保險。

　　Stress is often a factor in the development of long-term sickness.

　　心理壓力常常是形成長期病的一個因素。