sick in bed释义：

生病在床上

例句：

The old man has lain sick in bed for years.

那老者病卧于床好些年了。

sick in the bed释义：

卧病在床

例句：

It's a bore to be sick, and the novelty of lying in bed all day wears off quickly.

生病是件无趣的事，整天躺在床上的新鲜感很快就没了。