其中的with 表示原因，指因为流感而卧床。又如：

His face was red with embarrassment. 他尴尬得脸红了。

Diana was positively trembling with rage. 戴安娜气得全身发抖。

The air was thick with smoke. 空气里弥漫着浓浓的烟雾。

The children were already weak with exhaustion. 孩子们已经累得浑身无力了。