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。