illness和sickness可数吗

　　例句：

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

　　他在52年的工作时间里曾生过1星期的病。

　　We strongly recommend insuring against sickness or injury.

　　我们强烈建议投伤病保险。

　　I recommend you get insurance against sickness and unemployment.

　　我建议你办个疾病和失业保险。

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

　　心理压力常常是形成长期病的一个因素。